I need to change my boiler as it is now very old. I see that from
April 2005 it will be necessary to fit a condensing boiler.

I want to get away with as little change to the pumped CH and geavity
HW system that is currently in the house.

I will need a standard flue kit. My existing flue is balanced so must
I put in a flue stack up to roof level and does it have to be
insulated etc.?

Can I have an open vented pumped CH system and gravity HW with a
condensing boiler?

What other changes might I have to make?

Thanks for you time. I have looked through loads of posts but see
conflicting comments.

Andy Kaye

"Andy Kaye" wrote in message
om...
I need to change my boiler as it is now very old. I see that from
April 2005 it will be necessary to fit a condensing boiler.

I want to get away with as little change to the pumped CH and geavity
HW system that is currently in the house.

I will need a standard flue kit. My existing flue is balanced so must
I put in a flue stack up to roof level and does it have to be
insulated etc.?

Can I have an open vented pumped CH system and gravity HW with a
condensing boiler?

What other changes might I have to make?

Thanks for you time. I have looked through loads of posts but see
conflicting comments.

Andy Kaye

Sounds like you're in an identical situation to me. I'm having a new
condensing boiler fiitted in April. My existing boiler is 28 years old.

Every plumber that has been round to quote has said that the system needs
modifying, ie, changing from gravity semi fully pumped to a fully pumped
system with a system boiler.

IMHO, if i'm spending all the money on a nice new highly efficient
boiler...we may as well go the extra distance and spend a bit more to get it
running optimally. It's really not that much extra.

I don't disagree. But I want to know that my money is being spent
properly. If i know what is required I can sort of guess how much it
might cost.

If a bolier costs =A3800.00 and valve etc cost another =A3100 an it take
a day to install then =A31200 is a resonable price. But llokig at posts
here,it could be =A32000.

wrote in message
oups.com...
I don't disagree. But I want to know that my money is being spent
properly. If i know what is required I can sort of guess how much it
might cost.

If a bolier costs £800.00 and valve etc cost another £100 an it take
a day to install then £1200 is a resonable price. But llokig at posts
here,it could be £2000.

----------------------------------------------------------

I'm being quoted around £2100 inc VAT to do all the work required for me and
for one man it's a good two days work.

The work includes...

powerflush, boiler replacement to a Worcester Bosch 28 HE condensing system
boiler, remove and brick up old flue, replacing programmer with a 7 day one,
4 TRV's to be fitted - one to each bedroom rad, fitting a couple of
motorized valves and fitting one small radiator to the utility room.

It seems a good fair price especially as the work man is the only one listed
in my area as a recommended Worcester Bosch installer on their web site.

I had another local plumber quote me £3900 for almost exactly the same work.

Andy Kaye wrote:

I need to change my boiler as it is now very old. I see that from
April 2005 it will be necessary to fit a condensing boiler.

I want to get away with as little change to the pumped CH and geavity
HW system that is currently in the house.

You will need to get away from the gravity HW and go fully pumped...

I will need a standard flue kit. My existing flue is balanced so must
I put in a flue stack up to roof level and does it have to be
insulated etc.?

There is no reason it has to go up to the roof. Where (and at what
height) does it currently exit?

Can I have an open vented pumped CH system and gravity HW with a
condensing boiler?

Why would you want to? conversion to a fully pumped sealed system is
pretty straight forward.

What other changes might I have to make?

You ought to bring the controls up to standard, so a stat on the HW
cylinder, and room stat plus thermostatic rad valves elsewhere if not
already fitted.

Depending on the state of the rads and pipework, it may or may not take
well to being pressurised.



--
Cheers,

John.

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But you don't have to have a pressurised system, you can buy condensing regular boilers. I'll be fitting a regular condensing boiler open vent with open vent dhwc this week as a new installation, because it is a holliday flat so the frequent changes of user don't have to be educated about filling loops. Open vent systems though hasstle for the installer (particulalry if he designs his pipe runs badly) are more user friendly.

On this post don't forget all the above plus with a major change like upgrading the boiler the cylinder has to conform to part L 2002 also, so that undoubtedly needs changing.

Of course you can apply for exemption from Part L, say for instance you are 95 years of age and don't expect to live long enough to benefit from the extra capital cost.

Costs?

Very high quality condensing regular boiler (and horizontal flue) with 5 year manufacturer's parts and labour guarantee 800 gbp.

DHW Cylinder
141 gbp

S Plan (because it's the best) CH control system (includes everything you need) 76 gbp and a new pump 65 gbp.

TRV's from BBQ 5 gbp each

Pipework and fittings 200 gbp

cleanser and inhibitor 28 gbp

REmoval disposal of old boiler and cylinder? 200 gbp.

Labour two days for a quality heating engineer and his side kick; 800 gbp.

Extras? You may need new header tanks.

"Paul Barker" wrote in message
...

But you don't have to have a pressurised system, you can buy condensing
regular boilers. I'll be fitting a regular condensing boiler open vent
with open vent dhwc this week as a new installation, because it is a
holliday flat so the frequent changes of user don't have to be educated
about filling loops. Open vent systems though hasstle for the installer
(particulalry if he designs his pipe runs badly) are more user
friendly.

On this post don't forget all the above plus with a major change like
upgrading the boiler the cylinder has to conform to part L 2002 also,
so that undoubtedly needs changing.

Where is the reg that says a cylinder has to be updated if a new boiler is
being installed?

Of course you can apply for exemption from Part L, say for instance you
are 95 years of age and don't expect to live long enough to benefit from
the extra capital cost.

Costs?

Very high quality condensing regular boiler (and horizontal flue) with
5 year manufacturer's parts and labour guarantee 800 gbp.

DHW Cylinder
141 gbp

Always go for a quick recovery coil cylinder, part L is false economy. A
condesning boiler will greatly benefit from this giving beter economy. Also
a quick recovery cylinder is be downsized. Always have a DHW priority
system and a two stats on the cylidner to eliminate boiler cycling and give
one long efficient burn when re-heating. This is well worth it.

S Plan (because it's the best) CH control system (includes everything
you need) 76 gbp and a new pump 65 gbp.

TRV's from BBQ 5 gbp each

Wate of time as they don't last. Best get Danfoss from
http://www.bes.ltd.uk

Pipework and fittings 200 gbp

cleanser and inhibitor 28 gbp

REmoval disposal of old boiler and cylinder? 200 gbp.

Labour two days for a quality heating engineer and his side kick; 800
gbp.

Extras? You may need new header tanks.


--
Paul Barker


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"Paul Barker" wrote
| ... I'll be fitting a regular condensing boiler open
| vent with open vent dhwc this week as a new installation,
| because it is a holliday flat so the frequent changes of
| user don't have to be educated about filling loops.

I don't see why weekly or fortnightly tenants should need education about
filling loops. Pressurised systems should not need repressurising unless
there is something wrong like a leak or pressure vessel failure.

| Open vent systems though hasstle for the installer
| (particulalry if he designs his pipe runs badly) are
| more user friendly.

One particular reason for a pressurised system in your application, where
the property is, I surmise, likely to be unoccupied for periods of time, is
that if there is a leak the amount of water in a pressurised system is
finite. If a vented system leaks there is an unlimited amount of water to
cause damage because the system is continually replenished from the header
tank.

Owain

In article ,
Owain wrote:
One particular reason for a pressurised system in your application,
where the property is, I surmise, likely to be unoccupied for periods of
time, is that if there is a leak the amount of water in a pressurised
system is finite. If a vented system leaks there is an unlimited amount
of water to cause damage because the system is continually replenished
from the header tank.

If this really is a problem, you could fit a stopcock to the header tank
feed - under normal circumstances there will be enough water in the header
tank for a couple of years - if not more.

--
*I'm not being rude. You're just insignificant

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

"Dave Plowman (News)" wrote in message
...
In article ,
Owain wrote:
One particular reason for a pressurised system in your application,
where the property is, I surmise, likely to be unoccupied for periods of
time, is that if there is a leak the amount of water in a pressurised
system is finite. If a vented system leaks there is an unlimited amount
of water to cause damage because the system is continually replenished
from the header tank.

If this really is a problem, you could fit a stopcock to the header tank
feed - under normal circumstances there will be enough water in the header
tank for a couple of years - if not more.

Oh my God, look what this fool is saying. Only on the Internet.


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Thanks for the info John.

I will have to look up what is necessary to change the HW from gravity
to fully pumped.

I read that it is not a good idea to have too many thermostatically
controlled radiator valve as it cuts down the efficiency but we only
have them in bedrooms.

As for the original balanced flue it exits the house at chest level.
With a wall hung condensing boiler the exit for the flue will be at
about 7 ft. I didn't know if there were any building regs for the
condensing boiler flue like with conventional flues. I seem to
remember my father having to build an insulated stack up to the roof
in the past.

I expected to add a cylinder stat. and upgrade my room stat. and
chnage the programmer so I guess I am a little better prepared now.

Now to find a corgi fitter who doesn't charge the earth.

Andy Kaye wrote:

I read that it is not a good idea to have too many thermostatically
controlled radiator valve as it cuts down the efficiency but we only
have them in bedrooms.

Not really a problem with a modulating boiler since it simply reduces
its power output to mathc the reducing load, hence it maintains
operation in an efficent temperature range.

As for the original balanced flue it exits the house at chest level.
With a wall hung condensing boiler the exit for the flue will be at
about 7 ft. I didn't know if there were any building regs for the
condensing boiler flue like with conventional flues. I seem to
remember my father having to build an insulated stack up to the roof
in the past.

Therea are rules for how close the flue can be to windows etc, but these
are not that onerrous in most cases. 7" is good since it will be over
(most) peoples heads. It also does not want to be directed at a
neighbouring property if it is too close.

Culled from an Ideal install guide:

Terminal Position Minimum Spacing
1. Directly below or alongside an
opening window, air brick or other
ventilation opening 300 mm (12")
2. Below guttering, drain pipes or soil
pipes 25 mm ( 1")
3. Below eaves 25 mm ( 1")
4. Below balconies or a car port roof 25 mm ( 1")
5. From vertical drain pipes or soil pipes 25 mm ( 1")
6. From an internal or external corner or
to a boundary along side the terminal. 25 mm ( 1")
7. Above adjacent ground, roof or
balcony level 300 mm (12")
8. From a surface or a boundary
facing the terminal 600 mm (24")
9. From a terminal facing a terminal 1200 mm (48")
10. From an opening in a car port
(e.g. door or window) into dwelling 1200 mm (48")
11. Vertically from a terminal on the
same wall 1500 mm (60")
12. Horizontally from a terminal on the wall 300 mm (12")



--
Cheers,

John.

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"John Rumm" wrote in message
...
Andy Kaye wrote:

I read that it is not a good idea to have too many thermostatically
controlled radiator valve as it cuts down the efficiency but we only
have them in bedrooms.

Not really a problem with a modulating boiler since it simply reduces
its power output to mathc the reducing load, hence it maintains
operation in an efficent temperature range.

It is a problem. You need a by-pass valve which raises the return
temperature which reduces efficiency. You can get around this by isntalling
a flow switch abd timer. By-pass valves should not be on condesning boilers




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Doctor Evil wrote:

I read that it is not a good idea to have too many thermostatically
controlled radiator valve as it cuts down the efficiency but we only
have them in bedrooms.

Not really a problem with a modulating boiler since it simply reduces
its power output to mathc the reducing load, hence it maintains
operation in an efficent temperature range.


It is a problem. You need a by-pass valve which raises the return
temperature which reduces efficiency. You can get around this by isntalling
a flow switch abd timer. By-pass valves should not be on condesning boilers

It is better to not fit a TRV on the rad that shares a room with the
stat, then you solve the problem without extra switches and timers.




--
Cheers,

John.

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In article ,
John Rumm writes:

Culled from an Ideal install guide:

Terminal Position Minimum Spacing
1. Directly below or alongside an
opening window, air brick or other
ventilation opening 300 mm (12")

ISTR building regs bumps this up to 600mm minimum nowadays.

--
Andrew Gabriel

Andrew Gabriel wrote:
In article ,
John Rumm writes:

Culled from an Ideal install guide:

Terminal Position Minimum Spacing
1. Directly below or alongside an
opening window, air brick or other
ventilation opening 300 mm (12")


ISTR building regs bumps this up to 600mm minimum nowadays.

Still 300mm last time I looked

Can I have an open vented pumped CH system and gravity HW with a
condensing boiler?

No you can't.

Note that this requirement isn't about condensing boilers. There is already
a requirement to upgrade to fully pumped and controlled hot water cylinder
heating when replacing the boiler and has been for some years. So even if
you replace right now with a traditional boiler, it would be against
building regulations to keep the gravity hot water primary circulation.

Christian.