New boiler not heating radiators

lillywhite1

I got a new high efficiency boiler installed recently. The problem is that it is not heating all the radiators. There are three rads in an downstairs extension and only one of these heats at all while the other two do not get even warm.

The plumber says that it is a design flaw with the extension and it has something to with the way the extension was plumbed.

He said he coud try to improve the balance in the system but that was all he could do.

What should I do? Do I need to get a major job done?

Joey the lips

Was the rads working before the boiler was put in....


If so its the plumbers problem and tell him so.

Give him a reasonable amount of time to fix the problem then tell him if he has not that you will get another plumber to fix it and will be looking to him for the bill.

The plumber should have sized the boiler correctly for you.

lillywhite1

Of the three in the extension two of them had been working but I am not sure about the third one.

I am going to give him a ring again and see what he can do. He stressed when I called him yesterday that there was nothing he could do but try and rebalance the system (????) as there was a design flaw in the extension relating to the plumbing: he mentioned something about the three rads in the extension not being part of the main circuit but instead coming off the boiler or something like that.

There are only 10 rads in the whole house. Is it possible that the problem is down to the way the extension was plumbed in the first place?

Thanks for your help.

roy rodgers

turn off all the rads that are heating in the house and than see if the 3 in the extension heat up. If they do then turn on all the rads again and see do they keep heating. If they dont, the piping to the rads could be undersize.

lillywhite1

Thanks for the advice.

When i turned off all of the other rads the three in the extension heated up. When I turned on all of the others again the ones in the extension cooled down again.

Is it a major job to get the pipes changed? Is that the only solution?

Sparkpea

yes thats pretty much the only way to fix it and is a big enough job if its solid floors.

most extensions are plumbed wrong and done cheaply, 15mm pipes taken from 15mm pipes normally means only 1 of the rads will work and its normally the existing one unless the existing one is cut way down and the new one open full. each rad should be took from a 22mm+ flow and return pipe for best results.

I agree with the plumber that theres probably not alot he can do about it I've been in the same boat loads of times trying to fix others problems when an extension or conservatory was built.

If your system is pressurised he could change the pump to a 6m head pump and try it, if its not pressurised it might be worth doing it and try that, if still no better then change the pump also. but again this is trial and error. balance and system might also help.

lillywhite1

Thanks very much for the help. I will see about the pump etc.

It is actually my parents house and they are sleep in the extension so it is pretty important that they have heat in the bedroom and in the bathroom as there is a disabled shower in there and it is like a fridge at the moment.

If I leave some of the other rads off should the ones in the extension stay hot.

Dont fancy the thought of riping up the floors.

Thanks again.

Sparkpea

if you could post pics of pipework around the boiler or the pipes the plumber said is going to the extension it might help a little.

generally if he has said the pipes from the extension are direct to the boiler then there shouldnt be any problem in them heating as those 3 new ones should be one of the first to heat.

when the boiler was replaced was the pump also replaced? pic of pump would be good

it could be that if they are direct to the boiler then the pump isn't pumping as fast as it should or you could try turning it to setting number 3 as most are set to 2. 3 pumps faster than 2 so it might need to be a bit faster to get around the extension.

good luck hopefully you can find an answer on here without having to alter too much