Y Plan to Combi Conversion

[rossmelis]

Is it possible to convert an existing Y plan system to a combi HE in the loft. The boiler will go directly under the cupboard with the HW cylinder in.

If so, how would the plumber go about this?

I assume it would not be to much trouble as all the pipe work is already in the loft and airing cupboard(cold feed, hot water distribution, flow and return to CH off Cylinder is there) , just a case of re-routing some pipe work, take the gas up to the loft and install the Combi.

Also, what would be the typcal cost of the above.

PS I am doing this as apart of my course at college, so any help would be greatfull.

 

[marty]

Yeah this can be done by altering pipe work a bit . you would have to fit ramsey ladder , light & some flooring at boiler for service etc.

 

[heating-eng]

Is it possible to convert an existing Y plan system to a combi HE in the loft. The boiler will go directly under the cupboard with the HW cylinder in.

If so, how would the plumber go about this?

I assume it would not be to much trouble as all the pipe work is already in the loft and airing cupboard(cold feed, hot water distribution, flow and return to CH off Cylinder is there) , just a case of re-routing some pipe work, take the gas up to the loft and install the Combi.

Also, what would be the typcal cost of the above.

PS I am doing this as apart of my course at college, so any help would be greatfull.

very easy and common ..as for price it would very much depend on what boiler in fitted .this website gives you an idea on costs. also how much extra would be for taking out airing cuboard Cheap Boilers - New Boiler

 

[stevetheplumber]

hardest part of this job is finding a route for gas pipe up to loft external is often best
regs actually say loft hatch must be protected by a hand rail but im yet to see one

 

[LIFES A GAS]

There will most likely be the need to increase the size of the gas supply, also if your existing system is old you may need to replace rad valves if the old ones are not designed for pressurised systems.
Martin.

 

[rossmelis]

Hi Guys, thanks for your feedback.

I just want to clarify how how I would manage the flow and return for the CH, bearing in mind that the pipe work will be coming down from the loft.

I have attached a little picture to which I think is the correct way including HW draw off. The cold feed and supply is self explanatory.

Your thoughts would be appreciated, cheers again!

 

[Puddle]

Hi Guys, thanks for your feedback.

I just want to clarify how how I would manage the flow and return for the CH, bearing in mind that the pipe work will be coming down from the loft.

I have attached a little picture to which I think is the correct way including HW draw off. The cold feed and supply is self explanatory.

Your thoughts would be appreciated, cheers again!

well we are taking out the tank and cylinder
mains to the tank is diverted to mains supply to boiler
hot is connected to old vent and old tee to cylinder removed..though you may wish to run as much as posssible in 15mm to cut down on water content in pipework,to get quicker response at taps and less waste of hot water left in pipework
flow and return run down to cylinder cupboard,using old 22mm vent if you want for one run
link heating flow to old heating flow after removing old pump and motorised valve
link return to old cylinder return
remove boiler and cap of pipe work,make good wall
gas run to be made in 22mm,if meter outside run up outside wall,will have to be able to isolate gas supply from outside loft space so maybe drop/loop down with isolation valve to allow gas to be isolated
condensate pipe work will require running to hopefully plastic guttering or plastic soil,if problem maybe run down to old airing cupboard and into bathroom waste if next to cupboard
Power to boiler extended from airing cupboard to roof,with isolation in roof also,leaving isolation down stairs as well good idea
wireless room thermostat
ladder fixed access to roof
boarded out from opening to boiler ,with work area
as said rails around opening
cage around boiler or railed off area for protection,the loft is a storage area and if boiler not protected boxes,surf boards and rubber studded outfits ect can fall against,infringing on required clearances and ventilation requirements
fixed light for area
advise smoke detector
advise a pressure gauge fitted on system maybe in airing cupboard for easy checking,maybe filling loop as well fitted if mains running through old airing cupboard or maybe use old heating cold feed pipe work to bring mains down,just thoughts
all pipe work well lagged in roof space
if old wc supplied by tank,replace ball vale washers and possible inner jet
probably missed something that will be picked up to add to your check list

 

[Blackcatgas]

Condense pipe?, use a lift pump if that helps.

well we are taking out the tank and cylinder
mains to the tank is diverted to mains supply to boiler
hot is connected to old vent and old tee to cylinder removed
flow and return run down to cylinder cupboard,using old 22mm vent if you want for one run
link heating flow to old heating flow after removing old pump and motorised valve
link return to old cylinder return
remove boiler and cap of pipe work,make good wall
gas run to be made in 22mm,if meter outside run up outside wall,will require to drop/loop down with isolation valve to allow gas to be isolated from below without entering loft
condensate pipe work will require running to hopefully plastic guttering or plastic soil,if problem maybe run down to old airing cupboard and into bathroom waste if next to cupboard
Power to boiler extended from airing cupboard to roof,with isolation in roof also,leaving isolation down stairs as well good idea
wireless room thermostat
ladder fixed access to roof
boarded out from opening to boiler ,with work area
as said rails around opening
cage around boiler for protection
fixed light for area
advise smoke detector
advise a pressure gauge fitted on system maybe in airing cupboard for easy checking,maybe filling loop as well fitted if mains running through old airing cupboard or maybe use old heating cold feed pipe work to bring mains down,just thoughts
all pipe work well lagged in roof space
if old wc supplied by tank,replace ball vale washers and possible inner jet
probably missed something that will be picked up to add to your check list

Only if your fitting a Jaguar combi, or a potterton puma........

That was rubbish Il get my coat....


.......

 

[LIFES A GAS]

Same goes for these:

And dont forget to feed it.
Martin.

 

[fuzzy]

done it loads of times. all the pipework you need is in the cylinder cupboard and already in the loft if you have an indirect CW system.

I have run the gas pipe external before now to save going up down through walls and ceilings. Make sure its big enough and well clipped.

Oh, and once i capped off the old F&R to the old boiler which stopped the return of the circuit, didnt do that again!!!!!!!!!

 

[heating-eng]

done it loads of times. all the pipework you need is in the cylinder cupboard and already in the loft if you have an indirect CW system.

I have run the gas pipe external before now to save going up down through walls and ceilings. Make sure its big enough and well clipped.

Oh, and once i capped off the old F&R to the old boiler which stopped the return of the circuit, didnt do that again!!!!!!!!!

i did that many years ago on a bbu ..then i couldnt work out why the new boiler wasnt working ...

 

[fuzzy]

i did that many years ago on a bbu ..then i couldnt work out why the new boiler wasnt working ...

me to, i had to draw out what i had done. then it was obvious, i felt a right fool as i had been messing with the diverter valve in the boiler as the HW worked fine!!!!!!!!!!!!!!!!

 

[heating-eng]

me to, i had to draw out what i had done. then it was obvious, i felt a right fool as i had been messing with the diverter valve in the boiler as the HW worked fine!!!!!!!!!!!!!!!!

it was about 20 years ago when i did it

but i fitted new boiler on wall took me no time at all . took me longer to work out why it wasnt working LOL

 

[fuzzy]

it was about 20 years ago when i did it

but i fitted new boiler on wall took me no time at all . took me longer to work out why it wasnt working LOL

This was a new boiler also, thought i was being clever sorting a quick fault! took me a day to realise, oh the shame

 

[rossmelis]

Hi Guys

I must say this is first rate info!! Thank you!!

I believe we have covered every angle and potential problems with this type on conversion.

However, Fuzzy has just thrown a spanner in the mix. Initially, I thought capping off the existing F&R on the existing boiler would be okay as the flow off the existing boiler will not make a complete circuit since I will be connecting the new flow on where Port a should be and the old to be flow capped off (before air sep) in the airing cupboard. So are we saying the F&R on the existing regular boiler should be piped together, if so what is the reasoning?

I attach another picture, a picture in return would be even better!!

 

[Puddle]

go as you say rossmelis

Do not loop through old boiler pipes,just cap,in this instance
the heating flow is being picked up in airing cup,the old flow from boiler will be connected to nothing,so does not need capping really,just stops any drips from pipe work*
return is linked to old cylinder return and return at boiler caped off

if you linked,you would have to bring flow down from new boiler and tee into heating circuit in airing cup and also link to old flow from boiler after removing old motorized valve and pump,all you would do is form a heating loop under the floor doing nothing
the only other thing to check is if you have no heated towel rail fitted just after old pump ,so came on all the time,this would have to be linked into flow,you do not have to worry about were return joins,as still part of new system

The only time you would link flow and return from old boiler is if pump was fitted near boiler and you had towel rail or radiator fitted in pipe work between old boiler and cylinder cup,thus you would need to keep circuit to allow to operate

* as per your drawing you have capped at boiler,capped at airing cup,if fact all you do is run straight down and join to heating flow,there will be not tee before pump to your capped pipework

 

[fuzzy]

you are teeing in the new F&R before the tees to the old boiler so in your case you need to cap em off. If it were part of the new circuit it would need to be linked. A lesson here on conversions really, ensure you draw out the F&R to confirm a circuit.

 

[ISM]

Hi Ross again on a new account.

So essentially, we will have a dead leg on both F&R from the A/cup to old boiler. The flow will not be connect to the new system in anyway as capped off, the old return will be connected. However, capped off at old boiler and not creating a circuit.
In regards to the above diagram: the last Tee on the return is always the return off the cylinder?

 

[Mgrant]

done it loads of times. all the pipework you need is in the cylinder cupboard and already in the loft if you have an indirect CW system.

I have run the gas pipe external before now to save going up down through walls and ceilings. Make sure its big enough and well clipped.

Oh, and once i capped off the old F&R to the old boiler which stopped the return of the circuit, didnt do that again!!!!!!!!!

If you capped the old flow and return at the old boiler and tee'd in to the flow and return in a different place to take to the combi. Would this not be ok?

 

[rpm]

If you capped the old flow and return at the old boiler and tee'd in to the flow and return in a different place to take to the combi. Would this not be ok?

Jeeez James thats the best part of 5yrs ago. lol

 

[Mgrant]

I know I was just reading through some old threads.

 

[julesverne]

Holy thread revival bat man

 

[Mgrant]

If you capped the old flow and return at the old boiler and tee'd in to the flow and return in a different place to take to the combi. Would this not be ok?

Any advice on this?

 

[Mgrant]

Isn't it a case off taking out the 3port valve and connecting the heating flow to this to the flow to the heating? Then connecting the flow and return to the old boiler to the combi.