My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

Thanks

Jonathan

Jonathan wrote:
My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?


It's not ideal but it should work i guess.

All the radiators should be able to have TRV's as Combi systems normally have
an internal bypass circuit. You will be able to adjust the desired flow
temperature. So provided this isn't too high, the boiler will just modulate
or switch off when the flow temperature is reached.

Doesn't sound ideal to have the pump running 24x7 though....

chunkyoldcortina wrote:
Jonathan wrote:
My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?


It's not ideal but it should work i guess.

All the radiators should be able to have TRV's as Combi systems normally have
an internal bypass circuit. You will be able to adjust the desired flow
temperature. So provided this isn't too high, the boiler will just modulate
or switch off when the flow temperature is reached.

Doesn't sound ideal to have the pump running 24x7 though....

There are some combis that can be supplied with an internal time
clock/programmer - for instance Ideal Isar.

On Feb 26, 11:24*am, Jonathan wrote:
My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

Thanks

Jonathan

The combi could have a timer included in it. For example:-

http://www.ravenheat.co.uk/CSIPrimary.htm

"chunkyoldcortina" wrote in message
...
Jonathan wrote:
My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

It's not ideal but it should work i guess.

All the radiators should be able to have TRV's as Combi systems normally
have an internal bypass circuit.

You need a "control interlock", by law. That means a way of cutting out the
boiler when no heat is needed in the house. This is normally done by having
a room stat with no TRV on the rad. Having the boiler open up a by-pass and
cycle on itself is very inefficient and can lead to premature boiler
failure.

The stat can be a timer/stat, so timing solved. A combi cannot have TRVs
all around, unless there is an integral flow switch. Some Baxi models have
this feature, like the HE 133.

One way around not having an integral flow switch is install an auto
modulating Smart pump on the return pipe to the combi and flow switch just
after that. Wire the combis stat circuit through the flow switch. This
means you have two pumps in push me pull you configuration. If the combis
integral pump is on the return put the smart pump on the flow.

When the TRVs all close up the flow switch switches out the combi's pump and
burner and the Smart pump winds down. When the TRVs open up the Smart pump
winds up and switches in the flow switch which switches in the combi burner
and pump. No central stat then and TRVs all around. You use two pumps, so
it may be a good idea to put in a restrictor balancing valve on the CH
return to restrict the flow of the two pumps. Then the Smart pump will wind
down and not use a large amount of electrical energy.

chudford wrote:
On Feb 26, 11:24 am, Jonathan wrote:
My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

Thanks

Jonathan

The combi could have a timer included in it. For example:-

http://www.ravenheat.co.uk/CSIPrimary.htm


Looks like a good deal with the 3 year guarantee. I wonder why the
insurance company I use (Domestic&General) wants a hefty premium to
cover it for breakdown. Maybe they just load it according to the initial
price of the boiler. Anyone got any opinions about them?

"Stuart Noble" wrote in message
...
chudford wrote:
On Feb 26, 11:24 am, Jonathan wrote:
My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

Thanks

Jonathan

The combi could have a timer included in it. For example:-

http://www.ravenheat.co.uk/CSIPrimary.htm


Looks like a good deal with the 3 year guarantee. I wonder why the
insurance company I use (Domestic&General) wants a hefty premium to cover
it for breakdown. Maybe they just load it according to the initial price
of the boiler. Anyone got any opinions about them?

The company load it for only the Ravenheat? Ravenheat are generally a waste
of sheet metal. I believe one or two of the simple heating boilers are OK.
They also rebadge one I think, and this is OK too.

In one job they had reservations on a high flow combi because they wanted
DHW backup. To go for a cylinder or heat bank would have meant taking up
valuable space and more expense. A cheap backup option was a quality main
high flow combi and a cheapo B&Q £300 combi as backup. The backup was fitted
below the main combi (sizable under the stairs cupboard). To install the
cylinder and a new immersion cable and the rest would have been far, far
more expensive that the cheapo backup combi. The CU breaker, switch and
immersion and cable would have been more than the cheap combi.

They had full DHW & CH backup (OK DHW was reduced flowrate) and the same gas
supply was used for both as they would not be on at the same time - a throw
over switch was use to prevent both being on. The cheapo combi would be
used once in a blue moon, so no reliability problems. The pipework and
effort in installing the extra combi was negligible.

So cheapo combis have their uses.

In article ,
Doctor Drivel wrote:
In one job they had reservations on a high flow combi because they
wanted DHW backup. To go for a cylinder or heat bank would have meant
taking up valuable space and more expense. A cheap backup option was a
quality main high flow combi and a cheapo B&Q £300 combi as backup. The
backup was fitted below the main combi (sizable under the stairs
cupboard). To install the cylinder and a new immersion cable and the
rest would have been far, far more expensive that the cheapo backup
combi. The CU breaker, switch and immersion and cable would have been
more than the cheap combi.

They had full DHW & CH backup (OK DHW was reduced flowrate) and the same
gas supply was used for both as they would not be on at the same time -
a throw over switch was use to prevent both being on. The cheapo combi
would be used once in a blue moon, so no reliability problems. The
pipework and effort in installing the extra combi was negligible.

So cheapo combis have their uses.

Excellent idea. Cheap combis are known for their reliability - far better
than an immersion heater. And of course everyone has room for one along
with the main one.
Remind us of the planet you're from?

--
*I wonder how much deeper the ocean would be without sponges*

Dave Plowman London SW
To e-mail, change noise into sound.

Jonathan wrote:

My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for
such a system?

No, and it won't meet current building regs...

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

A better solution is to dispense with the timer and use a programmable
room stat. This allows selection of desired temperature through several
time periods in the day. Hence it does the job of stat, programmer, and
frost stat all in one. A basic one is about £20.

--
Cheers,

John.

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

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
In one job they had reservations on a high flow combi because they
wanted DHW backup. To go for a cylinder or heat bank would have meant
taking up valuable space and more expense. A cheap backup option was a
quality main high flow combi and a cheapo B&Q £300 combi as backup. The
backup was fitted below the main combi (sizable under the stairs
cupboard). To install the cylinder and a new immersion cable and the
rest would have been far, far more expensive that the cheapo backup
combi. The CU breaker, switch and immersion and cable would have been
more than the cheap combi.

They had full DHW & CH backup (OK DHW was reduced flowrate) and the same
gas supply was used for both as they would not be on at the same time -
a throw over switch was use to prevent both being on. The cheapo combi
would be used once in a blue moon, so no reliability problems. The
pipework and effort in installing the extra combi was negligible.

So cheapo combis have their uses.

Excellent idea. Cheap combis are known for their reliability - far better
than an immersion heater. And of course everyone has room for one along
with the main one.

Remind

Please eff off as you a complete and total idiotic plantpot.

In article ,
Doctor Drivel wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:

[drooling snipped]

So cheapo combis have their uses.

Excellent idea. Cheap combis are known for their reliability - far
better than an immersion heater. And of course everyone has room for
one along with the main one.

Remind us of the planet you're from?

Please eff off as you a complete and total idiotic plantpot.

Planet woodentop, then. Are they all barking mad?

--
*The modem is the message *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:

[drooling snipped]

So cheapo combis have their uses.

Excellent idea. Cheap combis are known for their reliability - far
better than an immersion heater. And of course everyone has room for
one along with the main one.

Remind us of the planet you're from?

Please eff off as you a complete and total idiotic plantpot.

Planet

Please eff off as you a complete and total idiotic plantpot.

On Thu, 26 Feb 2009 03:24:32 -0800, Jonathan wrote:

My builder is installing a combi boiler hot water/ heating system in a
holiday flat that we are planning to let out. He does not appear to be
fitting a room thermostat or any sort of timer. Is this normal for such
a system?

I can understand not having a room thermostat as all radiators (except
one) have TRVs but the lack of a timer concerns me. I don't want
enormous bills because the heating is on 24 hours a day.

Can anyone please advise me on what is normal?

Check the back of his CORGI card (Gas Safe card from 1 Apr) it should say
whether it has 'Energy Efficiency'. If it has then they should know and
act better. Timer, thermostat and TRVs are all needed. If it doesn't
they they shouldn't be installing a heating system.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

On Thu, 26 Feb 2009 13:15:51 +0000, chunkyoldcortina wrote:

All the radiators should be able to have TRV's as Combi systems normally
have an internal bypass circuit.

That's not correct for the combis I'm familiar with.



--
John Stumbles -- http://yaph.co.uk

Hypnotising Hypnotists Can Be Tricky