Installing new combi central heating system - DIY

Joined
24 Jul 2007
Messages
25
Reaction score
0
Location
Cheshire
Country
United Kingdom
Hi
We’ve recently bought our first house (which is more of a project! – lots of work needed) and finances mean must DIY as much as possible.
We currently have an old back boiler system with hot and cold water (plastic) tanks in a bedroom cupboard which we are thinking of replacing (along with a hideous 70’s gas fire attached to the back boiler) I’m thinking of having a crack at some of this myself. Obviously, being a plumbing novice, I will have a lot of research to do before starting but any help on these basic questions would be much appreciated:

1) Is this a realistic project for a DIYer or am I biting off more than I can chew!

2) From a ‘developers’ point of view (as we hope to trade up quite quickly) is it even worth replacing the system. The existing system does work and the house is only a modest 2 bed terrace worth about 85k when finished. Is the work likely to add more value than it costs?

3) I need to clarify what I can do myself by law. I was thinking I would get a CORGI pro in to do all the gas fitting. Am I right in thinking I’m ok to run any new non-gas pipe work and install / replace new radiators my self plus physically fitting the boiler without making the gas connections?

4) I have had a couple of people in already to quote but they can’t seem to agree on what needs doing – in particular if existing pipe work to radiators is up to the job or needs replacing. Its standard 15mm copper and looks ok to my untrained eye (apart from a couple of leeks round radiator valves which I intend to replace anyway) People trying to make work for themselves? Could do with some guidance on this.

5) Is there anything I can do myself regarding replacing the old gas fire and removing the back boiler to keep costs down?

6) New gas pipe work will be required as any new boiler will be in a different location and we want to install a gas cooker. Again, any sort of preparation work I can do here to keep costs down?

7) We currently have an electric shower which has seen better days. Any thoughts on if it is best to replace this like for like or incorporate the new shower so that the new boiler supplies the hot water to it?

8) What order to do things in? Better to have pro in first and then do new radiators, pipe work etc or best to do all the diy stuff first and then get pro in to finish off and get gas connections done?

9) Better to buy boiler myself or will Corgi guy get it cheaper?

10) Any website or book recommendations to help with this project?

All of the above assumes the new system will be a fairly basic Combi system with water tanks being removed to make room for the new boiler. I know there are a lot of opinions out there as to the pros and cons to this type of system, but as far as I can tell it’s the only real option for someone on a very (very!) tight budget ….. unless someone knows different.

Thanks to anyone who took the time to plough through that lot! I’m sure its pretty boring old ground to the more experienced readers but I don’t want to be caught out by new regs reading old threads. Any help will be Massively appreciated!
 
Sponsored Links
I'm quite a competant DIY'er but this is not something i'd attempt myself.

The main reason is that experienced plumbers will have alot of experience in routing pipework, making soldered joints etc and they will do it well and they will do it at 10 times the speed I could.

There are alot of regulations surrounding gas and i'm not sure routing a gas supply pipe is a job for a novice. I certainly wouldn't attempt it.

If the existing pipework and rads are ok then there is no need to replace these as long as it is not a single pipe system. A single pipe system is where all the rads are in series with each other.

Replacing rad valves is fairly easy to do when the system is drained.

As regards your question on added value, we have a back boiler with fire front and as it works fine and has been serviced properly there would be no value in upgrading it. Its not ideal but we've still managed to sell our house with it in.
 
You saythat
I have had a couple of people in already to quote but they can’t seem to agree on what needs doing – in particular if existing pipe work to radiators is up to the job or needs replacing. Its standard 15mm copper and looks ok to my untrained eye (apart from a couple of leeks round radiator valves which I intend to replace anyway) People trying to make work for themselves? Could do with some guidance on this.

I would suggest that you find some one who "knows" what needs doing and is prepared to work alongside someone who does not!!
The installer will in effect have to sign off this installation and therefore is accepting responsibility for it!!
Personally apart from removal of any redundant radiators etc, I would consider your participation in the project as a hindrance rather than help!!!
 
WELLY417 said:
1) Is this a realistic project for a DIYer or am I biting off more than I can chew!

Depends on how good you are and what the scope of the works are.

2) From a ‘developers’ point of view (as we hope to trade up quite quickly) is it even worth replacing the system. The existing system does work and the house is only a modest 2 bed terrace worth about 85k when finished. Is the work likely to add more value than it costs?

Probably. From a buyers point of view a shiney new combi is a plus - even if this isn't necessarily true!

3) I need to clarify what I can do myself by law. I was thinking I would get a CORGI pro in to do all the gas fitting. Am I right in thinking I’m ok to run any new non-gas pipe work and install / replace new radiators my self plus physically fitting the boiler without making the gas connections?

Most would say that you cannot fit the boiler - so what? this is a 30 minute job.

4) I have had a couple of people in already to quote but they can’t seem to agree on what needs doing – in particular if existing pipe work to radiators is up to the job or needs replacing. Its standard 15mm copper and looks ok to my untrained eye (apart from a couple of leeks round radiator valves which I intend to replace anyway) People trying to make work for themselves? Could do with some guidance on this.

It will probably be OK.

5) Is there anything I can do myself regarding replacing the old gas fire and removing the back boiler to keep costs down?

That doesn't save much either.

6) New gas pipe work will be required as any new boiler will be in a different location and we want to install a gas cooker. Again, any sort of preparation work I can do here to keep costs down?

You could theoretically install it all, without it being connected at either end, the corgi can then inspect and test it.

7) We currently have an electric shower which has seen better days. Any thoughts on if it is best to replace this like for like or incorporate the new shower so that the new boiler supplies the hot water to it?

You'll get a far better shower off the combi.

8 What order to do things in? Better to have pro in first and then do new radiators, pipe work etc or best to do all the diy stuff first and then get pro in to finish off and get gas connections done?

Hang the rads, install any new pipe-work and then get the corgi in, after due consultation with him/her.

9) Better to buy boiler myself or will Corgi guy get it cheaper?

Most will want to supply and fit.

10) Any website or book recommendations to help with this project?

This is quite a good one!

All of the above assumes the new system will be a fairly basic Combi system with water tanks being removed to make room for the new boiler. I know there are a lot of opinions out there as to the pros and cons to this type of system, but as far as I can tell it’s the only real option for someone on a very (very!) tight budget ….. unless someone knows different.

Don't make your budget too tight - you won't get anyone to do the work.

Thanks to anyone who took the time to plough through that lot! I’m sure its pretty boring old ground to the more experienced readers but I don’t want to be caught out by new regs reading old threads. Any help will be Massively appreciated!

You're more than welcome. Wait for 86 different opinions.
 
Sponsored Links
If the back boiler is working ok why change it if budget is tight?

Depending upon make/model of boiler it might be possible to get replacement fire front.
 
WELLY417 said:
4) I have had a couple of people in already to quote but they can’t seem to agree on what needs doing – in particular if existing pipe work to radiators is up to the job or needs replacing. Its standard 15mm copper and looks ok to my untrained eye (apart from a couple of leeks round radiator valves which I intend to replace anyway) People trying to make work for themselves? Could do with some guidance on this.

I'm currently upgrading the entire central heating system in my house (boiler and radiators) and had debated about the pros and cons of using existing pipework or replacing it.

I got my answer straight away when closer inspection lead to some of the soldered joints coming apart with my bare hands, with very little force required !

I'm changing to a combi (sealed) system so the existing pipework would never have been up to the job - just something to bear in mind if you want to swap over to a pressurised system.
 
AlanE said:
If the back boiler is working ok why change it if budget is tight?

Depending upon make/model of boiler it might be possible to get replacement fire front.

Replaced with what?
If the style is as stated you have no chance of finding a reasonable Fire!!
For the cost of a replacement firefront you can buy a cheapo combi !
The only customers I find who are happy with the fire on BBu are 70+ years old !!
The main reason for replacing most BBu is crappy fire front!!
 
Mike said:
"I'm currently upgrading the entire central heating system in my house (boiler and radiators) and had debated about the pros and cons of using existing pipework or replacing it.

I got my answer straight away when closer inspection lead to some of the soldered joints coming apart with my bare hands, with very little force required !

I'm changing to a combi (sealed) system so the existing pipework would never have been up to the job - just something to bear in mind if you want to swap over to a pressurised system."

At the risk of showing my total ignorance, why not just replace the bad joints. is there something inherently unsuitable about the pipe work ? Also, aren't all combi systems pressurised?
 
Replacing boiler/heating system will not increase your property's value, but will make it 'more desirable' as compared to others in the street.
 
go for it,move into my ex council place 8 years ago,no heating,two gas fires and it was freezing.thought we would wait till we could afford heating but by november we couldn't bear living there it was so cold and not homely.took the plunge and got a heatpack from a plumb centre.fitted the boiler one saturday,took a week off work and hung rads a nd done most of pipe work.a.mate plumbed the boiler to the gas and commissioned the system and then we had a lovely warm house which felt like home.done the whole 8 rad system for £800.worst part is lifting the perfect tongue and groove floorboards.good luck
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top