Replacing convetional with combi boiler

[Richard Hallam]

Im replacing my conventional (vented) boiler for a combi.

My boiler is downstairs in a utility room, upstairs in my airing cupboard the flow from the old boiler runs through the pump then into the 3 port valve, then either to the cylinder or off round the rads (no by-pass).

On removing the cylinder (pump, valve loft tanks etc) Im left with the return to boiler pipe from the cylinder (this joins the heating return somewhere unknown) and the old hot domestic to taps pipe. Can I simply cap both of these off in my airing cupboard (creating dead legs in both the heating and domestic hot )? These dead legs will both be under 5m, I want to avoid pulling up floorboards if possible.

If I do need to remove these dead legs, are there any best guesses as to where to start pulling up the floor boards?

Any help appreciated. Thank you

 

[fixitflav]

I'm replacing my conventional (vented) boiler for a combi.

IMO, don't.

 

[townfanjon]

Whos doing the job Richard ?

 

[Richard Hallam]

IMO, don't.

Don't change or don't cap, my descission to change is b

Whos doing the job Richard ?

I'm reasonably competent I wanted to do as much as possible myself (not the boiler). I have spoken to a couple of local gas safe plumbers who said they would be happy to work with me. I dare say I could ask there advice.

 

[fixitflav]

Don't change or don't cap?

Don't change. (Can't see the end of your sentence)

 

[Richard Hallam]

Don't change. (Can't see the end of your sentence)

Sorry, posted in error. I appreciate the cons (and pros) of changing to a combi as well the problems that can occur from changing from a vented to a pressurised system, nevertheless after considerable thought the decision to change has been made (I am happy to pull up my floor boards if need be). My post here is really only to get advice on the plumbing. Sorry to be blunt, but these posts are not helpful.

 

[fixitflav]

[QUOTE="Richard Hallam, post: 1002498, member: [/QUOTE]
OK, no problem, I was a bit tongue-in-cheek. I'm sure you looked into it before deciding. Just my opinion, partly based on a friend who runs a gas co and wouldn't have a combi in his house at any price. Don't know if he installs combis, but he definitely gets plenty of work from repairing them.

 

[Richard Hallam]

[QUOTE="Richard Hallam, post: 1002498, member:

OK, no problem, I was a bit tongue-in-cheek. I'm sure you looked into it before deciding. Just my opinion, partly based on a friend who runs a gas co and wouldn't have a combi in his house at any price. Don't know if he installs combis, but he definitely gets plenty of work from repairing them.[/QUOTE]
I can relate to that, my old glow worm space saver is as old as the house (30+ years), I know people who have had 3 boilers in the same period. Im only changing it as the flue is corroding (and of course its in-efficiency). My new baxi does come with a 10yr warranty - some piece of mind?

 

[ShaunCorbs]

You can cap them but best to remove the dead legs esp the hot water one

 

[fixitflav]

Im only changing it as the flue is corroding (and of course its in-efficiency).

OK, but if the rest of the system is OK you could change the boiler for a new heat-only condensing type.
But I don't want to labour the point, you've clearly thought it through.

 

[Richard Hallam]

Thanks Shaun, much appreciated. I will make an effort to try and remove these.