DIY Combi boiler and central heating system
 

Hi,

I am thinking of fitting my own Combi boiler and central heating
system(then a gas fitter connecting the gas).
Can anybody give me a simple overall description of how to do this.
1.We are thinking of fitting the new combi boiler in the bathroom,do i
simply connect a mains cold water supply to the boiler and tap in to
our existing hot water pipes with the DHW connection.
2.What size plastic pipes do you run for the central heating part,do
these reduce down at any point.
3.Do plastic pipes need lagging or are they thermally efficient.
4.I understand the need for a filling loop,what other stop valves or
relief valves are needed.
5.Do all combi boilers have a pump internally or do some not.
6.We are not planning on fitting radiators initially,can just the DHW
system be used then radiators connected afterwards.
7.Will any of our existing water pipes(hot/cold)to taps throughout our
house need replacing.
8.Do combi boilers come with installation/startup instructions for the
initial setup.
9.After the gas fitter has connected the boiler,should he set the
boiler up and check the hot water system or is this left to yourself.


From other posts i have read about DIY central heating it seems quite
possible with some DIY experience to undertake this job,i just need to
know of anything specific that should be done when fitting a system.

DIY Combi boiler and central heating system
 

On 23 Jan 2006 12:28:27 -0800, wrote:

Hi,

I am thinking of fitting my own Combi boiler and central heating
system(then a gas fitter connecting the gas).
Can anybody give me a simple overall description of how to do this.

1.We are thinking of fitting the new combi boiler in the bathroom,do i
simply connect a mains cold water supply to the boiler and tap in to
our existing hot water pipes with the DHW connection.
Pretty much though because your old system probably worked at low
pressure, you may need to change some of the pipe fittings and taps.

Check that the bathroom is big enough. You cannot put a boiler in Zone
1, and you may have to fit it in zone 3. Check the installation manual
for this.

2.What size plastic pipes do you run for the central heating part,do
these reduce down at any point.
22mm. Tee off to the radiators with 15mm or 10 mm.

3.Do plastic pipes need lagging or are they thermally efficient.
Lagging is still necessary under a suspended ground floor, in the loft
or outside.

4.I understand the need for a filling loop,what other stop valves or
relief valves are needed.
A liberal sprinkling of lever ball valves is useful for isolating
parts of the system. Don't get cheap ones - they leak. Don't get gate
valves - they seize.

You might need an extra expansion vessel depending on the size of your
system. You need a drain point somewhere near the lowest point in the
system with some sort of valve on it. An inline filter on the return
from the central heating is advisable.

5.Do all combi boilers have a pump internally or do some not.
As far as I know they all have a pump internally.

6.We are not planning on fitting radiators initially,can just the DHW
system be used then radiators connected afterwards.
Not very likely. You need some kind of bypass on the radiator circuit.
You could probably fit just one radiator initially.

7.Will any of our existing water pipes(hot/cold)to taps throughout our
house need replacing.
Joints that were previously under low pressure may need replacing.
Compression joints may just need tightening. If the toilet was fed
from a gravity system the ball valve may well fail and water will
constantly drip out through the overflow.

8.Do combi boilers come with installation/startup instructions for the
initial setup.
Yes.

9.After the gas fitter has connected the boiler,should he set the
boiler up and check the hot water system or is this left to yourself.
He will do it! He needs to check the pressure drop etc. when the
boiler is running.


From other posts i have read about DIY central heating it seems quite
possible with some DIY experience to undertake this job,i just need to
know of anything specific that should be done when fitting a system.
Yes it's quite possible...I did it with minimal experience. My best
advice would be to download the installation manual for the boiler you
intend to fit from the manufacturers website and read it from start to
finish before you do anything.

DIY Combi boiler and central heating system
 

Mr Fizzion wrote:
On 23 Jan 2006 12:28:27 -0800, wrote:

Hi,

I am thinking of fitting my own Combi boiler and central heating
system(then a gas fitter connecting the gas).
Can anybody give me a simple overall description of how to do this.

1.We are thinking of fitting the new combi boiler in the bathroom,do i
simply connect a mains cold water supply to the boiler and tap in to
our existing hot water pipes with the DHW connection.
Pretty much though because your old system probably worked at low
pressure, you may need to change some of the pipe fittings and taps.

Check that the bathroom is big enough. You cannot put a boiler in Zone
1, and you may have to fit it in zone 3. Check the installation manual
for this.

2.What size plastic pipes do you run for the central heating part,do
these reduce down at any point.
22mm. Tee off to the radiators with 15mm or 10 mm.

3.Do plastic pipes need lagging or are they thermally efficient.
Lagging is still necessary under a suspended ground floor, in the loft
or outside.

4.I understand the need for a filling loop,what other stop valves or
relief valves are needed.
A liberal sprinkling of lever ball valves is useful for isolating
parts of the system. Don't get cheap ones - they leak. Don't get gate
valves - they seize.

You might need an extra expansion vessel depending on the size of your
system. You need a drain point somewhere near the lowest point in the
system with some sort of valve on it. An inline filter on the return
from the central heating is advisable.

5.Do all combi boilers have a pump internally or do some not.
As far as I know they all have a pump internally.

6.We are not planning on fitting radiators initially,can just the DHW
system be used then radiators connected afterwards.
Not very likely. You need some kind of bypass on the radiator circuit.
You could probably fit just one radiator initially.

7.Will any of our existing water pipes(hot/cold)to taps throughout our
house need replacing.
Joints that were previously under low pressure may need replacing.
Compression joints may just need tightening. If the toilet was fed
from a gravity system the ball valve may well fail and water will
constantly drip out through the overflow.

8.Do combi boilers come with installation/startup instructions for the
initial setup.
Yes.

9.After the gas fitter has connected the boiler,should he set the
boiler up and check the hot water system or is this left to yourself.
He will do it! He needs to check the pressure drop etc. when the
boiler is running.


From other posts i have read about DIY central heating it seems quite
possible with some DIY experience to undertake this job,i just need to
know of anything specific that should be done when fitting a system.
Yes it's quite possible...I did it with minimal experience. My best
advice would be to download the installation manual for the boiler you
intend to fit from the manufacturers website and read it from start to
finish before you do anything.

DIY Combi boiler and central heating system
 

On Mon, 23 Jan 2006 12:28:27 -0800, chrishob wrote:

Hi,

I am thinking of fitting my own Combi boiler and central heating
system(then a gas fitter connecting the gas).
Can anybody give me a simple overall description of how to do this.
1.We are thinking of fitting the new combi boiler in the bathroom,do i
simply connect a mains cold water supply to the boiler and tap in to
our existing hot water pipes with the DHW connection.
2.What size plastic pipes do you run for the central heating part,do
these reduce down at any point.
3.Do plastic pipes need lagging or are they thermally efficient.
4.I understand the need for a filling loop,what other stop valves or
relief valves are needed.
5.Do all combi boilers have a pump internally or do some not.
6.We are not planning on fitting radiators initially,can just the DHW
system be used then radiators connected afterwards.
7.Will any of our existing water pipes(hot/cold)to taps throughout our
house need replacing.
8.Do combi boilers come with installation/startup instructions for the
initial setup.
9.After the gas fitter has connected the boiler,should he set the
boiler up and check the hot water system or is this left to yourself.


From other posts i have read about DIY central heating it seems quite
possible with some DIY experience to undertake this job,i just need to
know of anything specific that should be done when fitting a system.

The FAQs below may help to address some of these questions.

--
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

DIY Combi boiler and central heating system
 

1.We are thinking of fitting the new combi boiler in the bathroom,do i
simply connect a mains cold water supply to the boiler and tap in to
our existing hot water pipes with the DHW connection.

Basically yes, provided you've removed and sealed off the old gravity
gubbins.

2.What size plastic pipes do you run for the central heating part,do
these reduce down at any point.

It depends on your layout. There are various choices. You can run to
manifolds and then take microbore from there to individual rads. You can run
a 22mm trunk circuit and take 15mm or microbore to the rad valves. You can
subzone into several zones and run 15mm for each zone. It all depends on
your house layout and intended controls.

3.Do plastic pipes need lagging or are they thermally efficient.

When possible, lag all pipes, whether plastic, metal, central heating, cold
or DHW. This increases energy efficiency, prevents freezing and maintains
hot water at the tap after a longer pause between uses.

4.I understand the need for a filling loop,what other stop valves or
relief valves are needed.

The combi boiler will normally come with all the valves required, or
describe which are missing.

5.Do all combi boilers have a pump internally or do some not.

The vast overwhelming majority have an internal pump. I can't think of a
counterexample, but I bet someone can search out some obscure example.

6.We are not planning on fitting radiators initially,can just the DHW
system be used then radiators connected afterwards.

Normally this is OK, although you may need to check if the boiler requires
some sort of heat dumping capacity in the heating circuit.

7.Will any of our existing water pipes(hot/cold)to taps throughout our
house need replacing.

If they do, then they were on their last legs anyway and you now have an
opportunity to search for failing fittings at your own convenience.

8.Do combi boilers come with installation/startup instructions for the
initial setup.

Normally, although this can require some specialist equipment that your
CORGI fitter will need to do.

9.After the gas fitter has connected the boiler,should he set the
boiler up and check the hot water system or is this left to yourself.

Let them do it. It won't take long and it means he can sign your benchmark
book and use expensive or unusual equipment for the checks (i.e. gas
analysers, manometers).

Christian.

DIY Combi boiler and central heating system
 

Thank you for all your advice,i am sure i now have the incentive to
start the job myself.Thanks again

DIY Combi boiler and central heating system
 

wrote in message
oups.com...
Thank you for all your advice,i am sure i now have the incentive to
start the job myself.Thanks again


Before you start, find a gas fitter willing to do just the gas. Several I
spoke to were only willing to do the complete job.

DIY Combi boiler and central heating system
 

HELP!!!!!!!!!!!!!!!

I have fitted a combi condensing boiler,i have all the connections
fitted as per installation manual.i have filled the central
heating(which is actually just 1 rad at the moment)with the filling
loop till the guage read 1.5bar.

The combi boiler has a switch to select DHW or DHW/Central heating.

The problem is when i try to pull hot water from my taps,the burner
lights and burns for approx 10-15 secs,the pressure guage rises to
approx 3-4 bar and a small relief valve on the top of the boiler
discharges hot steam.

There is no hot water from the taps.

I am sure everything is connected as it should be,Please help.

DIY Combi boiler and central heating system
 

On 29 Jan 2006 11:47:11 -0800 wrote :
I am sure everything is connected as it should be,Please help.

Have you forgotten to open one of the isolating valves (if it's like my
Glow-worm with screwdriver valves on each pipe)

--
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
[Latest version QSEDBUK 1.12 released 8 Dec 2005]

DIY Combi boiler and central heating system
 

On Sun, 29 Jan 2006 11:47:11 -0800, chrishob wrote:


HELP!!!!!!!!!!!!!!!

I have fitted a combi condensing boiler,i have all the connections
fitted as per installation manual.i have filled the central
heating(which is actually just 1 rad at the moment)with the filling
loop till the guage read 1.5bar.

The combi boiler has a switch to select DHW or DHW/Central heating.

The problem is when i try to pull hot water from my taps,the burner
lights and burns for approx 10-15 secs,the pressure guage rises to
approx 3-4 bar and a small relief valve on the top of the boiler
discharges hot steam.

There is no hot water from the taps.

I am sure everything is connected as it should be,Please help.


I don't think this is the main flow/return isolators as
1) This happens in DHW and
2) The symptoms are too extreme.

I'd go for checking that the pump is operating and that it has been bled.
Clearly the auto air vent is working.

Make and model might help a bit too.


--
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

DIY Combi boiler and central heating system
 

Hi

How do i bleed the pump.

The model is a ravenheat csi 85a t condensing combi.

Personally i think i have air trapped somewhere in the boiler,when the
burner does fire popping/air sounds come from the boiler as the
pressure guage rises.

Thank You

DIY Combi boiler and central heating system
 

Hi

How do i bleed the pump.

The model is a ravenheat csi 85a t condensing combi.

Personally i think i have air trapped somewhere in the boiler,when the
burner does fire popping/air sounds come from the boiler as the
pressure guage rises.

Thank You

DIY Combi boiler and central heating system
 

"Ed Sirett" wrote in message
n.co.uk...
On Sun, 29 Jan 2006 11:47:11 -0800, chrishob wrote:


HELP!!!!!!!!!!!!!!!

I have fitted a combi condensing boiler,i have all the connections
fitted as per installation manual.i have filled the central
heating(which is actually just 1 rad at the moment)with the filling
loop till the guage read 1.5bar.

The combi boiler has a switch to select DHW or DHW/Central heating.

The problem is when i try to pull hot water from my taps,the burner
lights and burns for approx 10-15 secs,the pressure guage rises to
approx 3-4 bar and a small relief valve on the top of the boiler
discharges hot steam.

There is no hot water from the taps.

I am sure everything is connected as it should be,Please help.


I don't think this is the main flow/return isolators as
1) This happens in DHW and
2) The symptoms are too extreme.

I'd go for checking that the pump is operating and that it has been bled.
Clearly the auto air vent is working.

Make and model might help a bit too.


--
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



The pressure relieve valve is different to the auto air vent. Have you
removed the dust cap from the auto air vent?


John

DIY Combi boiler and central heating system
 

i have found the problem,the pump was'nt running.

Just for future reference i assume pumps in new boilers are prone to
sticking,all i did was tap the pump with a screwdriver and off it went
circulating the central heating water.


John wrote:
"Ed Sirett" wrote in message
n.co.uk...
On Sun, 29 Jan 2006 11:47:11 -0800, chrishob wrote:


HELP!!!!!!!!!!!!!!!

I have fitted a combi condensing boiler,i have all the connections
fitted as per installation manual.i have filled the central
heating(which is actually just 1 rad at the moment)with the filling
loop till the guage read 1.5bar.

The combi boiler has a switch to select DHW or DHW/Central heating.

The problem is when i try to pull hot water from my taps,the burner
lights and burns for approx 10-15 secs,the pressure guage rises to
approx 3-4 bar and a small relief valve on the top of the boiler
discharges hot steam.

There is no hot water from the taps.

I am sure everything is connected as it should be,Please help.


I don't think this is the main flow/return isolators as
1) This happens in DHW and
2) The symptoms are too extreme.

I'd go for checking that the pump is operating and that it has been bled.
Clearly the auto air vent is working.

Make and model might help a bit too.


--
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



The pressure relieve valve is different to the auto air vent. Have you
removed the dust cap from the auto air vent?


John

DIY Combi boiler and central heating system
 

On Sun, 29 Jan 2006 14:22:41 -0800, chrishob wrote:

Hi

How do i bleed the pump.

The model is a ravenheat csi 85a t condensing combi.

Personally i think i have air trapped somewhere in the boiler,when the
burner does fire popping/air sounds come from the boiler as the
pressure guage rises.

Bleeding the pump is pretty much required and/or best practice on all
combi/system boiler commissioning.
The pump has a removable disc which is the bleed plug for the pump.
If you had bled the pump first perhaps it might not have stuck?



--
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