No central heating - help!

[VenusStarr]

Repost from chat...

Hi

Putting a call out for any heating / plumbing experts please.

We recently moved house and have been having central heating issues. The boiler is an ideal 30 combi. All the radiators were mismatched and we had an intense banging / tapping whenever the heating was on or off but all radiators worked. Although didn't throw much heat out.

We have recently upgraded all the radiators to double convector (all were single panel before). We also added a radiator at the top of the stairs, as there was no heating from front door up stairs so that area was freezing!

Since the radiators have been replaced we've had issues. Initially the radiators upstairs were working but not downstairs. So we turned thermostats on each rad upstairs down and this seemed to push the heat to downstairs rads. But next morning we had no heating (timer). Have tried balancing rads by adjusting the valves, that was a fail. Currently have no heating at all :(

Plumber who did the work feels it may be a boiler issue. Changed pump but that made it worse and boiler seemed to be struggling. Put old pump back on. It seems that boiler is coming on when we have set the timer but is on for about 2 minutes and then clicks off - pipes in boiler too hot to touch (coming out of pump). It repeats this for the whole time we've set the heating to be on but no radiators work. If we manually go round and turn valves off and on we can get heat but the next time heating is due on rads are cold.

I spoke to ideal who said initially it could be our pipes but when I said the above about boiler constantly firing up she said maybe diverter valve and worst case PCB.

So, we are struggling with what to do next. The plumber said he would flush pipes / system when he fitted but actually didn't do this. It's very grim and miserable in our house. Just want to be warm. Hot water is fine.

Help!

you've changed the radiators and now some of them don't work.

Did you take the opportunity to give it a chemical clean?

How skilled and qualified was the person who did it?

Is the pump to hot to hold? Are the pipes on both sides of it equally hot? Or is the pump hotter than the pipes?

Observe the big pipes coming out of the boiler. When the heating is "on" one of them should be "too hot to hold" and one of them should be "too hot to hold for long." Are they?

ah, I see system not cleaned. If this was included in the quote, do you mean you paid for a clean and it wasn't done? What did the plumber say when you asked why not?

I'm guessing the radiators were old. How old?

Thanks for replying.

The house is 30 years old. I'm not sure how old the system is though. We have an extension and the plumber said in the extension the pipes are plastic. It was built in 1999. House built 1984.

The plumber has done lots of work for us before. He included flush in quote but on the day of fitting there was a pipe issue and we did have a leak. He spent a few hours replacing the section of pipe so didn't get chance - was 9pm when he left.

The pipe coming out of pump is too hot to hold. The pipes coming out of the boiler, one is stone cold and the other like a lukewarm cup of tea.

then it is not circulating.

I don't know the layout of your pump and its pipes. can you post a photo?

If a pump is seized, or dry, or blocked, or if one of its service valves is closed or broken, it can be hotter that the pipes (due to the electric current circulating inside it).

The lukewarm pipe might just have a bit of warm water in it due to convection.

You say it is a combi, so there is no hot water cylinder.

How many radiators do you have?
Do you know if the plumber changed the valves?
The initial banging of the radiators that you had was/is due to thermostatic valves being fitted the wrong way around. If the TRV/thermostatic head is fitted to the return side and not the flow side, this will cause banging and other problems.
Did you tell your plumber about the banging? If you did, then, he needs to come back and do the job properly.
Also, is he a plumber or a gas safe engineer?
If he is just a plumber, he should not be messing with your boiler.

Hi. Thanks for coming back. He is gas safe registered and has done lots of jobs for me over the years. The banging pipes was inherited abd we didn't know til we moved in.

He has been this week and flushed the system and whatever the issue was, it has now cleared. All radiators are now working to their full capacity. So it seems it was a pipe issue, perhaps a blockage and no issue with the boiler. Heating came on as programmed / expected this morning. He's also resolved the banging pipes.

Thanks for your help! :)