"JimGC" wrote in message
...
Bear with me a moment ... I'm shocked at the cost of running
my small flat's combi boiler compared to my previous
terraced house boiler which had a hot water tank. The cost
has doubled (3bd house HW/CH with 4 occupants was £360pa
over the year, 1 bd flat combi HW/CH with 1 occupant ran up
£60 in December alone!) The flat is fairly modern (1982) in
good condition, and I have the water/ch on from 6-9am and
from 4-11pm, turning it off when CH gets too hot. Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.

The reason for posting here is that I have already asked
about the inability of the boiler to provide a constant flow
of hot water. (CH seems to be very hot whenever it's on
whatever the thermostat on the boiler is set to).

Is it possible that the boiler has faulty thermostats and is
failing to provide constant hot water, but also using way
too much gas to feed the CH? Or am I just paying the price
for having this kind of boiler? Is it possible that I'm
using the combi boiler in the wrong way, and that these
fixed timing settings are not appropriate to combis?

You are not heating the water with the timer when using a combi. It may be
you need thermostatic radiator valves and a room thermostat fitting to make
the system much more efficient, especially with the comment you have to turn
the boiler off when the CH gets too hot. The TRVs I fitted payed for
themselves in no time.

Read
http://www.diyfaq.org.uk/contents.html

Adam

ARWadsworth wrote:
"JimGC" wrote in message
...
Bear with me a moment ... I'm shocked at the cost of running
my small flat's combi boiler compared to my previous
terraced house boiler which had a hot water tank. The cost
has doubled (3bd house HW/CH with 4 occupants was =A3360pa
over the year, 1 bd flat combi HW/CH with 1 occupant ran up
=A360 in December alone!) The flat is fairly modern (1982) in
good condition, and I have the water/ch on from 6-9am and
from 4-11pm, turning it off when CH gets too hot. Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.

The reason for posting here is that I have already asked
about the inability of the boiler to provide a constant flow
of hot water. (CH seems to be very hot whenever it's on
whatever the thermostat on the boiler is set to).

Is it possible that the boiler has faulty thermostats and is
failing to provide constant hot water, but also using way
too much gas to feed the CH? Or am I just paying the price
for having this kind of boiler? Is it possible that I'm
using the combi boiler in the wrong way, and that these
fixed timing settings are not appropriate to combis?

You are not heating the water with the timer when using a combi. It
may be
you need thermostatic radiator valves and a room thermostat fitting
to make
the system much more efficient, especially with the comment you have
to turn
the boiler off when the CH gets too hot. The TRVs I fitted payed for
themselves in no time.

Read
http://www.diyfaq.org.uk/contents.html

Adam

Are you paying for the gas via a prepayment meter? If so, the charge
rate
could be set too high.

JimGC wrote:

Bear with me a moment ... I'm shocked at the cost of running
my small flat's combi boiler compared to my previous
terraced house boiler which had a hot water tank. The cost
has doubled (3bd house HW/CH with 4 occupants was £360pa
over the year, 1 bd flat combi HW/CH with 1 occupant ran up
£60 in December alone!) The flat is fairly modern (1982) in
good condition, and I have the water/ch on from 6-9am and
from 4-11pm, turning it off when CH gets too hot. Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.

Given that you currently have the heating on, and many months of the
year you don't, I would expect to the difference between worst and best
months to be closer to 90% (i.e. most hours of the day you won't be
using any hot water and hence the boiler will be using no gas at all).

So a sample of costs taken from one month like this tell you nothing
really.

The reason for posting here is that I have already asked
about the inability of the boiler to provide a constant flow
of hot water. (CH seems to be very hot whenever it's on
whatever the thermostat on the boiler is set to).

That sounds like you do not have full thermostatic control in place
(i.e. room stat, and thermostatic radiator valves on all rads (except
the one in the room with the room stat).

Is it possible that the boiler has faulty thermostats and is
failing to provide constant hot water, but also using way

What do you mean by failing to provide constant hot water exactly? (i.e.
it works when the tap is first turned on, but the goes completely cold,
or does it run warm but not as hot as when you started etc).

There are several issues he

Firstly the thermostat for hot water in a combi just sets the upper
limit on the temperature. i.e. if you are using hot water it should not
supply it at a temperature exceeding that set on the stat.

The lower limit is usually set by the laws of physics. The boiler can
provide heat at a rate governed by its basic design (tell us the
make/model number and we can give you more info). The more powerful the
boiler, the more water it can heat in a given time. Hence if you ask for
a small flow of hot water it will supply it at a temperature governed by
the HW stat. As you turn the tap on more, you reach the limit of the
boilers power where even running flat out it can still not heat the
water to the stat temperature and the temperature of the water will
begin to fall. Select a high enough flow rate and it will not be able to
heat it enough to get it to a usable temperature.

There is yet one more issue, that there can be times when you are asking
for a small amount of hot water that the boiler is producing heat too
fast such that it would end up exceeding the stat temperature an hence
it has to turn off its burner. Some combis also use a relatively
insensitive flow switch which requires a good flow of water to be
requested before they will switch to hot water mode.

The moral of the story is that you need to choose your combi carefully
since there are lots of crap combis on the market, with too little
power, and lots of quirks when running. Alas if you landlord made the
choice for you you can probably guess what end of the market he went for!

too much gas to feed the CH? Or am I just paying the price
for having this kind of boiler? Is it possible that I'm

All things being equal with the boilers efficiency, there is no reason
for a combi to be less efficient than a system boiler with a hot water
cylinder. In fact it will tend to be more efficient since there is less
risk of you loosing energy from the stored hot water.

Having said that, any boiler can be run inefficiently with poor (or no)
control systems. You can also get a large variation in basic efficiency
between different boilers (i.e. the worst will give perhaps 70p worth of
heat for every pounds worth of gas, the best will give over 96p worth of
heat).

using the combi boiler in the wrong way, and that these
fixed timing settings are not appropriate to combis?

Could well be.

I plan to get a CORGI man in early in the new year to give
it the once over, landlord or not!

May help.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"JimGC" wrote in message
...
Bear with me a moment ... I'm shocked at the cost of running
my small flat's combi boiler compared to my previous
terraced house boiler which had a hot water tank. The cost
has doubled (3bd house HW/CH with 4 occupants was £360pa
over the year, 1 bd flat combi HW/CH with 1 occupant ran up
£60 in December alone!) The flat is fairly modern (1982) in
good condition, and I have the water/ch on from 6-9am and
from 4-11pm, turning it off when CH gets too hot. Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.

The reason for posting here is that I have already asked
about the inability of the boiler to provide a constant flow
of hot water. (CH seems to be very hot whenever it's on
whatever the thermostat on the boiler is set to).

Is it possible that the boiler has faulty thermostats and is
failing to provide constant hot water, but also using way
too much gas to feed the CH? Or am I just paying the price
for having this kind of boiler? Is it possible that I'm
using the combi boiler in the wrong way, and that these
fixed timing settings are not appropriate to combis?

I plan to get a CORGI man in early in the new year to give
it the once over, landlord or not!


In a block of flats - two absurd questions? )

Are you reading *your* gas meter?

Is another flat connected to your meter?

Keith G. Powell

In article , JimGC wrote:
Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.

FWIW the gas consumption for each quarter averaged over the last ten
years here has been Feb bill: 45%; May: 32%; Aug: 8%; Nov: 15%

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm

"JimGC" wrote
| This flat is a 1982 conversion and the boiler is almost
| certainly the original Worcester Heatslave 2+. I have
| checked it for CO and it's okay, my landlord's agent tells
| me it is checked annually.

The landlord's agent might tell you that, but by law they MUST give you a
copy of the Landlord's Gas Safety Certificate.

Owain

"JimGC" wrote in message
...
Bear with me a moment ... I'm shocked at the cost of running
my small flat's combi boiler compared to my previous
terraced house boiler which had a hot water tank. The cost
has doubled (3bd house HW/CH with 4 occupants was £360pa
over the year, 1 bd flat combi HW/CH with 1 occupant ran up
£60 in December alone!) The flat is fairly modern (1982) in
good condition, and I have the water/ch on from 6-9am and
from 4-11pm, turning it off when CH gets too hot. Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.


Can you clarify exactly what you mean by you have the water/ch on?
Are you perhaps using a two channel programmer in error as most combis have
the HW permanently available regardless of the timer function for the
central heating. In this case perhaps the installer wired up the two channel
programmer so that ch is on even if the programmer thinks it is switching
the hot water. Try to tell us what make and model of combi, what make and
model of programmer etc you have installed.


The reason for posting here is that I have already asked
about the inability of the boiler to provide a constant flow
of hot water. (CH seems to be very hot whenever it's on
whatever the thermostat on the boiler is set to).

CH on some combis is a fixed temperature the thermostat on the front is for
hot water, however you could have two adjustable thermostats again it
depends on the make and model of combi.


Is it possible that the boiler has faulty thermostats and is
failing to provide constant hot water, but also using way
too much gas to feed the CH? Or am I just paying the price
for having this kind of boiler? Is it possible that I'm
using the combi boiler in the wrong way, and that these
fixed timing settings are not appropriate to combis?

See above

JimGC wrote:

This flat is a 1982 conversion and the boiler is almost
certainly the original Worcester Heatslave 2+. I have
checked it for CO and it's okay, my landlord's agent tells
me it is checked annually.

Now I am a bit confused... the only "heatslave 2" models I could find
are all conventional boilers and not combis. If yours is one of those
then that would suggets that you have a hot water cylinder somewhere.

(A combi heats the mains cold water directly - there is no stored hor
water).

I plan to turn the CH off and put the thermostat to High
then try to run a bath. I think this would have happened in
the autumn anyway (admittedly with the thermostat on low)
and cold water after a few minutes still happened.

Again witha combi this is normally a non issue. It has a CH mode and a
HW one. When you turn on the hot tap the boiler goes to HW and stays
there until you turn off the tap. Hence you get no heating when dawing
hot water anyway.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

JimGC wrote:

HW/CH selection:
----------------
HW All day/CH Off
HW All day/CH Twice
HW All day/CH All day
HW Twice/CH off
HW Twice/CH Twice
HW Twice/CH All day

I usually have it on HW Twice/CH Twice.

Is this programmer built into the boiler or separate?

If it is built in, then I susspect were are not talking about a combi
boiler here at all, since the concept of HW twice makes no sense. With a
combi the HW should always be available.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
JimGC wrote:

HW/CH selection:
----------------
HW All day/CH Off
HW All day/CH Twice
HW All day/CH All day
HW Twice/CH off
HW Twice/CH Twice
HW Twice/CH All day

I usually have it on HW Twice/CH Twice.


Is this programmer built into the boiler or separate?

If it is built in, then I susspect were are not talking about a combi
boiler here at all, since the concept of HW twice makes no sense. With a
combi the HW should always be available.

If the Worcester Heatslave is the machine I'm thinking of it does indeed
have a CH + HW programmer, and it is a combi.

Some combis come on from time to time to keep the water in the heat
exchanger hot so you have really instantaneous hot water when you turn
on a hot tap, so I guess this boiler uses the HW programmer setting to
determine when to do this. If the diverter valve is on the blink it
might just explain why it carries on heating up for 10 minutes, and also
whey you only get lukewarm water after the initial spurt of scalding hot
water.

It's probably also well past its sell-by date.

On Mon, 03 Jan 2005 00:22:55 GMT, JimGC
strung together this:

Now I am a bit confused... the only "heatslave 2" models I could find
are all conventional boilers and not combis. If yours is one of those
then that would suggets that you have a hot water cylinder somewhere.

Ah well, thanks - any more suggestions or help will be very
welcome!

Hmm, from information I've found it could be either so it's a draw!

From some spares lists I've found it would appear that it is one of
those conventional boilers with the pump and valves built into it. I
think I've worked on a couple before, is it the one with a big turn
dial programmer on the right? I could be way off the mark here but it
is late!
--

SJW
Please reply to group or use 'usenet' in email subject

John Stumbles wrote:

If the Worcester Heatslave is the machine I'm thinking of it does indeed
have a CH + HW programmer, and it is a combi.

There seems to be a huge number of "heatslaves" some combi and some not.
Obviously decided that once they have a good name they ought to stick
with it!

Some combis come on from time to time to keep the water in the heat
exchanger hot so you have really instantaneous hot water when you turn
on a hot tap, so I guess this boiler uses the HW programmer setting to
determine when to do this. If the diverter valve is on the blink it

Yup could be...

(My Isar does the pre tempering bit, but it is not something you can
turn off as such)

might just explain why it carries on heating up for 10 minutes, and also
whey you only get lukewarm water after the initial spurt of scalding hot
water.

It's probably also well past its sell-by date.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

JimGC wrote:
John Stumbles wrote:


If the Worcester Heatslave is the machine I'm thinking of it does indeed
have a CH + HW programmer, and it is a combi.


Now I've checked a little further, I'm sure it is. It's the
programmable deluxe model, circa 1982!

....

It's probably also well past its sell-by date.


Absolutely. If I owned this flat it would be replaced
tomorrow. As I don't, I'm not quite sure where I stand.
Should the owner replace or repair it?

Do you mean: should they do _something_ about it, or do you mean which?
I assume it's the landlord's appliance (it'll say so on the landlord's
gas safety certificate - which they _have_ given you a copy of, haven't
they?!) so it's up to them to sort it out (though that's a matter
between you and them and any tenancy agreement you have, as with any
other repairs). As such I wouldn't be getting any repairs done off my
own bat, though you may have to get a repairer in to testify that it's
faulty to have leverage to get your landlord to deal with it.

At £1000+ for the
replacement, I'm not sure they'll take kindly to that.. !
But I'm certainly not paying £1000 in a flat with a short
term arrangement such as I have right now ..

If they can get it repaired (i.e. parts available and appliance is safe
to use) then fair enough: once it's fixed it shouldn't be desperately
expensive for you to run even if it's a pilot light model (which I think
it is). However it's not going to last much longer so IMHO it would be a
bit short sighted of your landlord to patch it up rather than replace
it. But that's landlords for you :-)

JimGC wrote:

Now I am a bit confused... the only "heatslave 2" models I could find
are all conventional boilers and not combis. If yours is one of those
then that would suggets that you have a hot water cylinder somewhere.


Ah! Now I'm confused too - but that's why I wrote to the
group! The only Heatslave boilers I could find on a

Yup, if you want confusing here is the place to come ;-)

websearch were described as combi - I also wrote to
Worcester Bosch Technical support describing the problem
have received the following reply:

"Thank you for your recent enquiry. Switch off the C/H
demand and allow to cool, then with a demand for DHW check
for power (230v AC) at terminal T4. If power present, it
would indicate a possible fault with the DHW priority
thermostat. If no power present, check the diverter valve
for let by to C/H."

(the fault finding info you got from WB would establish if the diverter
valve is getting the right signal to switch to HW mode. The diverter is
the bit of a combi that will "divert" the heated water away from the
heating circuit, and toward (typically) a secondary heat exchanger to
heat the water for the taps)

Didn't make a lot of sense to me, but he didn't contradict
my description of the boiler as a combi.

If you look at the Sedbuk boiler database thingy (follow the link at the
bottom of Tony Bryer's post to download a copy), they list some 35
different "heatslave" boilers. Some are combis, and some not.

So it is not too supprising that they did not contradict your
description given the range of boilers with the same name is vast.

The Heatslave 2 G50 is shown in two versions - one conventional flue,
one balanced. Neither are combis. Both have a lowish power output of
under 15kW. Production date is shown as 1984 which sounds like the right
sort of ball park.

The maintenance and installation instructions for this
boiler (hidden in an old box!) doesn't explicitly say it's
one or the other, but it only talks of a feed and expansion
cistern with no indication of a water tank. In fact it talks

Again feed and expansion suggests an open vented heating system. Many
combis would use a sealed system. Details of these he

http://www.makewrite.demon.co.uk/SealedCH.html

more about flow rate regulation etc which I assume is
related to combis - it gives an Optimum Flow rate through
the heat exchanger of 3gpm (whatever that is!)

They could be talking about a flow rate through the boilers heat
exchanger (i.e. the bit that transfers heat from the flame to the water)
of three gallons per minute. Typically the heating system is a closed
loop of pipework (and radiators) with a pump to circulate the water.
Each pass made by the water through the boiler will raise its
temperature a "bit" (the size of the "bit" will depend on many factors,
but 10 to 20 degrees C per pass is quite common).

If they were talking about the flow rate delivered by the HW side of a
combi then 3gpm (or 13.5 litres/min) would suggest a pretty powerful
boiler (say 35kW or more). None of the heatslaves seem to have that sort
of power.

I think it is a combi, (specifically, the Worcester
Heatslave 2+ G50 Deluxe) though I'm happy to be proved wrong
if it's not. I suspect my next move is to get a CORGI
engineer in to do the above checks and give the thing a once
over - not just for safety but for operating efficiency. I
wonder whether this is my responsibility or the landlord?

Ah well, thanks - any more suggestions or help will be very
welcome!

I could be wrong, but from your descriptions I would guess you have a
conventional boiler. Which would mean you also have a hot water cylinder
somewhere (airing cupboard?), and there would be a pump somewhere.

If that is the case, then there could be a number of ways the whole
thing is plumbed up, and hence a number of ways for it to go wrong.
Either way describing your problem to a plumber who can actually look at
the thing should get you closer to a solution.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Stumbles" wrote
| JimGC wrote:
| Absolutely. If I owned this flat it would be replaced
| tomorrow. As I don't, I'm not quite sure where I stand.
| Should the owner replace or repair it?
| Do you mean: should they do _something_ about it, or do you mean which?
| I assume it's the landlord's appliance (it'll say so on the landlord's
| gas safety certificate - which they _have_ given you a copy of, haven't
| they?!) so it's up to them to sort it out (though that's a matter
| between you and them and any tenancy agreement you have, as with any
| other repairs).

Although for a short term rent it should be the landlord's responsibility
(possibly even if the tenancy agreement says differently). The landlord
can't let an uninhabitable house, which is what a house without hot water is
considered to be nowadays. CAB might be a good point of contact, or some
councils have housing advice services that will deal with private sector
rents.

| As such I wouldn't be getting any repairs done off my
| own bat, though you may have to get a repairer in to testify that it's
| faulty to have leverage to get your landlord to deal with it.

It is probably against the tenancy agreement for the tenant to make any
alteration to the property; if the OP does any work on the boiler the
landlord might claim it is damaged and pursue the full costs of replacement
against the tenant :-(

| If they can get it repaired (i.e. parts available and appliance is safe
| to use) then fair enough: once it's fixed it shouldn't be desperately
| expensive for you to run even if it's a pilot light model (which I think
| it is). However it's not going to last much longer so IMHO it would be a
| bit short sighted of your landlord to patch it up rather than replace
| it. But that's landlords for you :-)

If it can be patched up to last until the warmer weather that might be
preferable to leaving a tenant without heating.

Owain

"JimGC" wrote
| I suspect my next move is to get a CORGI engineer in to
| do the above checks and give the thing a once
| over - not just for safety but for operating efficiency. I
| wonder whether this is my responsibility or the landlord?

It is your landlord's duty to provide you with a copy of the current annual
Landlord's Gas Safety Certificate. Failure to do so is a criminal offence.
It is also his responsibility to keep the heating and hot water systems in
usable order which I think includes telling you how to work them. Operating
efficiency (cost of running) is not an obligation, however, and will not be
checked by a safety inspection.

Owain

"JimGC" wrote in message
...
"John" wrote:

Can you clarify exactly what you mean by you have the water/ch on?
Are you perhaps using a two channel programmer in error as most combis
have
the HW permanently available regardless of the timer function for the
central heating. In this case perhaps the installer wired up the two
channel
programmer so that ch is on even if the programmer thinks it is switching
the hot water. Try to tell us what make and model of combi, what make and
model of programmer etc you have installed.

It's a Worcester Heatslave 2+ from 1982 (when these flats
were converted, I believe). As it's a rented flat I won't be
likely to have it replace but I'm sure I can persuade the
landlord to have it fixed, if possible!

It has the following settings:

Programme:
-----------
Off
Constant
Programme (timer with 1-on,2-off,3-on,4-off)

Temp:
------
High-Medium-Low

HW/CH selection:
----------------
HW All day/CH Off
HW All day/CH Twice
HW All day/CH All day
HW Twice/CH off
HW Twice/CH Twice
HW Twice/CH All day

I usually have it on HW Twice/CH Twice.

Ah then you do have a two channel programmer, the Heatslave is fairly
unusual in this respect. Most folks would run this device HW all day, CH
twice (YMMV) That way you can use hot water at any time you are awake i.e.
dawn till bedtime. The heatslave has a primary hot water "store" which
remains hot while the boiler is on duty and this is pumped around a
secondary heat exchanger whose job is to use the high temperature primary
water to heat up the secondary (tap) water.

For the test tonight, I ran a bath with it set to HW All
Day/CH Off, with Temp set to High, and the programme to
Constant. Same story: the burner is going like the clappers
(heard, not seen) but after a couple of minutes max of very
hot water it gets cooler until lukewarm after 5 minutes.
Burner still going like clappers, but radiators have cooled
down.

From the above I'm beginning to suspect that you may have an excessive flow
rate for your secondary (tap) water and what is happening is the heat
removed from the store is not replaced as fast as you are taking it away. It
is possible also that your burner is not producing heat at the full rate it
should be but I'd look at the tapwater flow rate before diving into the
combustion side

Given what I've read here it seems very strange that the
burner is on (easy to hear it fire up) when only the HW is
selected, and nothing is drawing on the water supply.

Not really it is charging up the heatstore or replacing losses when it
slowly cools down


Hope this helps with some ideas!
Thanks...

To start with take a two gallon (9litre) bucket and fill it from your
fastest flowing hot tap - usually the bathtap. Time this operation to a
reasonable degree of accuracy and let us know what your results are. The
more recent heatslaves are probably much better in all ways than the old
ones but once you have carried out the timing test allow the heatstore to
recover then try reducing the flow rate to something around two gallons a
minute and see if the running out of hot water still persists. I don't have
the performance figures of the heatslave to hand but you may find them in
the installation and service booklet if its still with the boiler (faint
hope). Otherwise Worcester can no doubt provide this info.

"John Stumbles" wrote in message
...
JimGC wrote:
John Stumbles wrote:


If the Worcester Heatslave is the machine I'm thinking of it does indeed
have a CH + HW programmer, and it is a combi.


Now I've checked a little further, I'm sure it is. It's the
programmable deluxe model, circa 1982!

...

It's probably also well past its sell-by date.


Absolutely. If I owned this flat it would be replaced
tomorrow. As I don't, I'm not quite sure where I stand.
Should the owner replace or repair it?

Do you mean: should they do _something_ about it, or do you mean which?
I assume it's the landlord's appliance (it'll say so on the landlord's gas
safety certificate - which they _have_ given you a copy of, haven't
they?!) so it's up to them to sort it out (though that's a matter between
you and them and any tenancy agreement you have, as with any other
repairs). As such I wouldn't be getting any repairs done off my own bat,
though you may have to get a repairer in to testify that it's faulty to
have leverage to get your landlord to deal with it.

At £1000+ for the
replacement, I'm not sure they'll take kindly to that.. !
But I'm certainly not paying £1000 in a flat with a short
term arrangement such as I have right now ..

If they can get it repaired (i.e. parts available and appliance is safe to
use) then fair enough: once it's fixed it shouldn't be desperately
expensive for you to run even if it's a pilot light model (which I think
it is). However it's not going to last much longer so IMHO it would be a
bit short sighted of your landlord to patch it up rather than replace it.
But that's landlords for you :-)

See my other post on this unit. The more modern heatslaves suffer from
excessive numbers of plastic bits but generally are relatively simple if a
bit on the bulky side. I could see everything about this combi even at its
age being replaceable. In short unless the landlord is feeling particularly
flush its gonna be a fixit job. :-)

"JimGC" wrote in message
...
John Rumm wrote:

So a sample of costs taken from one month like this tell you nothing
really.

Fair point, and if I optimistically assume the winter
quarter as 50% of the annual bill, and assume December (with
holidays) is 50% of the Winter quarter, I get an annual bill
of £240 or £20pm which is much better, though my 3bd
townhouse has an annual bill of £360 with 2-4 occupants!

What do you mean by failing to provide constant hot water exactly? (i.e.
it works when the tap is first turned on, but the goes completely cold,
or does it run warm but not as hot as when you started etc).

Get a thermostatic mixer valve inbetween the boiler DHW out and the hot
water taps, that will minimize the temperature swings, but will not do
anything to the boiler not being able to keep up with a large load!

Combi boilers are a good idea on paper, because they make for a very simple
installation (ie. you can get rid of the DHW tank) but are seldom up for the
job simply because they cannot provide enough hot water when you want to
take a good long shower.


I have this in another thread, but briefly if I try to run a
bath (however slowly) the hot tap runs very hot for 30secs
then drops from warm to cold in 5 minutes or so. At best I
can only get half a bath of comfortably hot water.

Then get a thermostatic showervalve, that will use only the hot water
required to satisfy your requirements regardless of water temperature
comming from the boiler. The boilr will still have to be able to keep up
with your use of hot water, but you don't get scalded and then waste a lot
of hot water waiting for it too cool down or waste it trying to get the
shower set correctly.


There are several issues he

Firstly the thermostat for hot water in a combi just sets the upper
limit on the temperature. i.e. if you are using hot water it should not
supply it at a temperature exceeding that set on the stat.

I have the boiler thermostat on Low (out of L-M-H). I can
here the thermostat click if I turn the dial up and down,
but I still get steaming water for 30 seconds or so when I
ri8unthe tap with the thermostat on Low. I tried running a
bath with HW/CH running on High with no difference to the
temperature of the flow.

That maybe because some combi boilers come with a small hot water tank that
is used to small loads, ie. a little bit of hot water to wash hands, but
when a larger load comes along the boiler will fire up and try to keep up
with the load.


The lower limit is usually set by the laws of physics. The boiler can
provide heat at a rate governed by its basic design (tell us the
make/model number and we can give you more info).

This flat is a 1982 conversion and the boiler is almost
certainly the original Worcester Heatslave 2+. I have
checked it for CO and it's okay, my landlord's agent tells
me it is checked annually.

The more powerful the
boiler, the more water it can heat in a given time. Hence if you ask for
a small flow of hot water it will supply it at a temperature governed by
the HW stat. As you turn the tap on more, you reach the limit of the
boilers power where even running flat out it can still not heat the
water to the stat temperature and the temperature of the water will
begin to fall. Select a high enough flow rate and it will not be able to
heat it enough to get it to a usable temperature.

I plan to turn the CH off and put the thermostat to High
then try to run a bath. I think this would have happened in
the autumn anyway (admittedly with the thermostat on low)
and cold water after a few minutes still happened.

Yes but in autumn the incomming water was probably warmer so less energy was
required to heat the water to the required temperature, my incomming water
swings between 5°C and 9°Cdepending on season...


/Morten



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.825 / Virus Database: 563 - Release Date: 30/12/2004

I have a Worcester Heatslave in a rented property - with the same symptoms.
The problem is almost certainly the diaphragm in the diverter valve.It's
rubber and perishes. You find that the CH works fine, but the DHW is
affected.
You should find that the best temporary measure is to have the central
heating ON, when you run the bath, and turn the flow down until the hot
water runs hotter, and for longer.
With the CH off - the DHW runs colder!
The part is still available - diaphragm around £15, ot the complete diverter
valve around £70. Get the part number from Worcester and you can get from
Curzon - a nationwide chain 0870 5103030.
My tenants are putting up with this because I'm replacing the boiler when
the weather's a bit warmer , as well as carrying out other refurbishments.
Yours is an old boiler, but could still give years of service, it's not
necssarily a reflection on the landlord(s).

--
-------------------------------------------------------------------------------------
view my philatelic items for sale on ebay at:
http://tinyurl.com/l32i
"JimGC" wrote in message
...
Bear with me a moment ... I'm shocked at the cost of running
my small flat's combi boiler compared to my previous
terraced house boiler which had a hot water tank. The cost
has doubled (3bd house HW/CH with 4 occupants was £360pa
over the year, 1 bd flat combi HW/CH with 1 occupant ran up
£60 in December alone!) The flat is fairly modern (1982) in
good condition, and I have the water/ch on from 6-9am and
from 4-11pm, turning it off when CH gets too hot. Dec. is
the worst month of the year measure usage, but even if it
all drops 50% for the rest of the year, it's still too high
for my liking.

The reason for posting here is that I have already asked
about the inability of the boiler to provide a constant flow
of hot water. (CH seems to be very hot whenever it's on
whatever the thermostat on the boiler is set to).

Is it possible that the boiler has faulty thermostats and is
failing to provide constant hot water, but also using way
too much gas to feed the CH? Or am I just paying the price
for having this kind of boiler? Is it possible that I'm
using the combi boiler in the wrong way, and that these
fixed timing settings are not appropriate to combis?

I plan to get a CORGI man in early in the new year to give
it the once over, landlord or not!

Thanks,
Jim

--------------------------------------------------
To email go to my address and take out the dog ...

"JimGC" wrote in message
...

Thanks for all of that - noted. I think th only sensible
thing is to get the agent to call in an engineer and have
the whole thing assessed. I've spoken to the neighbours who
had/have similar boilers, and they say they're all on their
way out and need to be replaced. One neighbour had hers
moved as well as replaced and it cost her £2500!

Complicated - and expensive - business.

No not really, it's fairly simple as long as you understand how things are
done, unfortunately there's alot of work done that doesn't need to be done
and quite a few cases of wrong advices and outright day-robbery by people
who knows against the rest of us who don't know.

Greed, that's what it is, people wan't more and are getting quite good at
abusing the people who dont know...


/Morten




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.825 / Virus Database: 563 - Release Date: 31/12/2004

Morten wrote:

What do you mean by failing to provide constant hot water exactly? (i.e.
it works when the tap is first turned on, but the goes completely cold,
or does it run warm but not as hot as when you started etc).


Get a thermostatic mixer valve inbetween the boiler DHW out and the hot
water taps, that will minimize the temperature swings, but will not do
anything to the boiler not being able to keep up with a large load!

If there is no hot water coming from the boiler then a thermostatic
mixer is not going to do anything useful, it can't heat the water!

Combi boilers are a good idea on paper, because they make for a very simple
installation (ie. you can get rid of the DHW tank) but are seldom up for the
job simply because they cannot provide enough hot water when you want to
take a good long shower.

Sorry, but that is nonsense really. One of the things that most combis
are very good at is showers. The time they can be poor (the lower
powered ones at least) if providing the high flow rate of water required
to run a bath quickly, or to provide for several users simultaneously.

I have this in another thread, but briefly if I try to run a
bath (however slowly) the hot tap runs very hot for 30secs
then drops from warm to cold in 5 minutes or so. At best I
can only get half a bath of comfortably hot water.


Then get a thermostatic showervalve, that will use only the hot water
required to satisfy your requirements regardless of water temperature
comming from the boiler. The boilr will still have to be able to keep up
with your use of hot water, but you don't get scalded and then waste a lot
of hot water waiting for it too cool down or waste it trying to get the
shower set correctly.

He would be better spending the money to get the boiler to work. If it
is a combi, it obviously has a fault.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
...

Get a thermostatic mixer valve inbetween the boiler DHW out and the hot
water taps, that will minimize the temperature swings, but will not do
anything to the boiler not being able to keep up with a large load!

If there is no hot water coming from the boiler then a thermostatic
mixer is not going to do anything useful, it can't heat the water!

Correct, but it will make the too hot water last longer because you're
mixing it with cold water intil the required temperature is reached. When
the incomming water gets to cold you're back to sq1 but it will take longet
to reach this state...


/Morten




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.825 / Virus Database: 563 - Release Date: 30/12/2004

Morten wrote:

If there is no hot water coming from the boiler then a thermostatic
mixer is not going to do anything useful, it can't heat the water!


Correct, but it will make the too hot water last longer because you're
mixing it with cold water intil the required temperature is reached. When
the incomming water gets to cold you're back to sq1 but it will take longet
to reach this state...

With a stored water system this will be true, with a combi that is
working correctly it should not make any difference since the hot should
not run out...

(Still worth having a mixer mind you, to protect you from scalding /
freezing every time a tape gets turned on elsewhere when you are in the
shower!)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/