Central heating issues???

[Fozzy9967]

Hi
So got a quick question for the plumbers out there, I've recently had my 28kw boiler moved from my bathroom upstairs to my kitchen downstairs and the heating pipes that ran up the wall were replaced. They were 22mm copper to 15mm plastic. I'm a little worried tho....
I checked tonight and I have 22mm copper pipe connecting to the boiler but as soon as it goes under the floor, out of view, it gets reduced to 15mm plastic....
Is this ok??? I have 4 radiators upstairs and 4 radiators down stairs all being fed by 15mm flow and return pipes. Can someone please tell me if this is ok??? I'm lost, all the research I've done says I should have 22mm flow and return and should have 15mm branches off to each radiator. Please help

 

[securespark]

I'm sorry, I don't know but I think you'll get a better response in the boiler forum.

 

[SammyInnit]

all the research I've done says I should have 22mm flow and return and should have 15mm branches off to each radiator.

I think that's the answer mate.

 

[Dan Robinson]

All depends on the system load.

 

[jeff the gasman]

What Dan said.

 

[petit_pablo]

Does it work? If so, yea its fine.

 

[dilalio]

After converting to a combi, the pipework in my house goes all over the bloody place and changes more than a whore's drawers... it works perfectly and was a no-brainer considering the upheaval of changing it all!

 

[Fozzy9967]

That's the problem, downstairs radiators don't work. One one radiator warms up a little in the bottom corner next to the TRV but all other downstair radiatorsare cold. Currently the flow and return feeding the radiators are 22mm steel/copper mixed pipe (from the 60s I think).
So I've got 22mm copper from boiler to underfloor, drops down to 15mm plastic under the floor to a Tee that sends a 15mm upstairs and a 15mm to the downstairs. The downstairs then goes from a 15mm plastic to the 22mm old flow/return and old 15mm branches off the old 22mm to the radiators.

Hope you can all follow that because I'm getting alittle lost trying to describe it haha

I'm also renavating the house so floors coming up are no problem.

 

[dilalio]

Were they working before is the big question! If not, then that is a separate job from a boiler change - it all depends what they quoted you for! If they were, then you should obviously get the fitters back to at least investigate!

 

[Fozzy9967]

Yeh they were but after the boiler got moved they didn't, problem was that I got the boiler moved last summer, so didn't find out the radiators wouldn't work until winter came and by then I was busy taking them off the walls (so didn't think too much about them not working) so I could skim and paint the walls. Now that I'm putting them back on the walls I want to get them working again. I think I'm going to change the flow and return from the boiler to all 22mm and branch 15mm off that. Fingers crossed this will solve my problem.

 

[dilalio]

I don't think I'd get much work if I told my customers that my fingers were crossed on the outcome of a job I was about to undertake for them

But that is the difference between DIY and EIY (Earning it Yourself)!

 

[Fozzy9967]

Haha yah dilalio I know but I've tried to get a straight answer and I've just been running round in circles. Had a few quotes from plumbers and it was between £400 and £750 just to get my downstairs pipes replaced. Some people said it needed to have 22mm flow and return and others (cheaper quotes) said 15mm pipes will be fine. I'm starting to feel like there is no one really knows. But as a keen DIYer I'm going to have a go myself and hope for the best, if I mess up I will get the plumbers in. Worst that can happen is I get a swimming pool under my floor.

 

[dilalio]

If you have the 'seams' open in your property (free of furniture and all walls and floors accessible) then I would definitely take the opportunity to tidy up the plumbing. But check the rads and system for other issues than just pipe bores and runs... give it a good mains flush and check for concretions, sludge etc.

 

[Razor900]

Turn all the upstairs rads off and see if they get hot

 

[Fozzy9967]

Quick update,
I've redone the downstairs with the plastic 22mm flow and return with 15mm feeds to the radiators..

Good news, the heating system works a charm now. Loads of black sludge came out the old pipework and was even in the new pipework I just had put in last summer... it's now as clean as a whistle