Problems with old boiler - is it the pump?

[prettybird]

This might be long - but I'm hoping that @pigletjohn (or anyone else with expertise) might be able to help.

We have an old Ideal Standard boiler - probably 30 years old, but it's an absolutely solid workhorse and the only thing that goes wrong with the boiler itself is the thermocouple needing to be replaced every so often (which reminds me - I need to buy another couple ) We'd initially (when we moved in 20 years ago) planned on replacing it, but we had a few heating engineers out and they said not to bother as it was such a solid system and just to wait until it fully broke down - and wouldn't even quote us!

It is up in the attic floor and heats a large Victorian conversion (attic floor and "main" floor, which is actually the 1st floor, with 3 large reception rooms, large kitchen, bathroom and small study. There used to be a radiator in the bottom hallway but we took it out for some reason about 15 years ago and never got round to replacing it - partly because the heating worked better without it (I think).

The radiator main the main floor are all large double finned ones without thermostatic valves (2 in the lounge, 1 in the dining room, 1 in the bedroom and 1 in the kitchen, with a small one in the study and another one not even double finned in the bathroom. The ones in the attic floor are newer, triple finned, much smaller but very effective

We'd had 15 years of the heating working fine (especially after an old boss of mine told us we could replace the thermocouple ourselves ) - especially after the bottom hallway radiator was taken out.

About 5 years ago, there was a small leak, apparently from a perished seal on a valve leading into the pump, which resulted in a small amount of water ingress into the kitchen below. We got heating engineers out to repair it - not ones we knew but with a water leak it was a bit urgent

The lad who came out said it was the valve and went off to get a new one. He then couldn't get it operating again.

To cut a long story short - he was here for a day, trying to work out the electrics He then got his gaffer in who was then here for another 2 days, , telling us it was wired incorrectly (despite the fact that we'd never had a problem with the timer/thermostat) and eventually saying that the pump was broken and replacing it.

It has never worked properly since . We can get the attic radiators roasting - but we can essentially only get heat to one radiator at a time on the "main" floor. It's as if the pump is not circulating and it's only gravity fed. So we have to choose which room to keep warm.

Is the red (new) one the same power as the old one (the green one)? Or could the valves (like the one right at the start of these shenanigans which had apparently perished and was replaced) be part of the problem?

Dh has drain and flushed and drained and flushed the system (including putting in inhibitor) over the years.

All dh wants for Christmas is a (whole) warm house

We have someone (who we trust) coming out tomorrow (again) but I thought it was worth asking for any advice in case that helps.

"We can get the attic radiators roasting - but we can essentially only get heat to one radiator at a time on the "main" floor. It's as if the pump is not circulating and it's only gravity fed. So we have to choose which room to keep warm. "

turn off ALL the hot ones. Do some of the cold ones now heat up? If so, turn those off as well. Do some of the remaining cold ones now heat up? And continue.

Should also add that the hot water we do get out the taps is roasting and plenty of it (although the damage that they did to the hot water tank - which was initially just one of those things in that they knocked a perished seal on the hot water tank but then tried to replace it without roasting the stiff nut - we got our tried and tested plumber in to sort that one but he is not Corgi registered )

is your hot-water cylinder surprisingly hot?

post photo of the pipes and devices around the boiler and cylinder.

Look for a motorised valve

www.screwfix.com/search?search=port+valve

PigletJohn

I have never needed you but I think you are fantastic for the way you help out people on here.

Dh has tried all sorts of combinations with the upstairs radiators off/on and it doesn't make much difference.

Water is hot - but can be adjusted down, eg in summer, when the mains water is warmer (I believe - I've never done it as dh does it ) There are actually two linked hot water tanks (you can see the other one just behind what I'd initially thought was the only one).

I can see one motorised valve, but I can't see how many pipes it is attached to. Two, or three?

Your pump will feed a pipe that goes to the hot water cylinder(s) and another that goes to the radiators. You need to find and identify them. Then you need to feel how hot they are.

I think quite likely the pump is sending most of the heat from the boiler to the cylinder(s) meaning there is not enough remaining to go round all the radiators. The motorised valve(s) are supposed to cut off supply to the cylinder(s) when it (they) are hot. I think this is probably not happening.

I'll go back upstairs and look (might be half an hour as SIL has just come in) . Not sure I can post any more photos.

I do know that with our new thermostat (which was one of the attempted solutions), I can hear the boiler cutting out regularly even though it's not reached anywhere near the temperature we've set the thermostat at).

There's what I presume is a second motorised valve underneath and behind the pump (comes off the pipe coming down from the pump just above the one that you can see clearly in the picture). The top valve goes to the hot water tank, the lower valve a presume goes to the radiators (it's all a jumble of pipes but that one "disappears")

In the absence of photos, I've attempted

     [pump]
        II               [hot water tank]
        II = [valve]===II

[valve]=II
II====[I presume the radiators]

Dh says that if anything, the (one) radiator that we have open on the main floor works better when the upstairs ones are opened up

(Don't think it's really relevant but for your amusement, the boiler is an Ideal Standard E Type CF).

when the boiler and pump are running, does the pipe to the cylinder(s) ever cool down, while the pump to the radiators stays hot?

the cylinder should stop drawing heat once it reaches the target temperature set on the cylinder stat you can see peeping out of the cylinder jacket. The cylinder thermostat should click when it reaches temperature, and the motorised valve should briefly whirr as it closes.

I'll go up and listen/feel.

The boiler is currently firing (but has just stopped) but I didn't hear anything from the pump or the valves.

Both sets of pipes are equally hot.

FWIW - the ambient temperature in the room (the hall) where the thermostat is currently located (it's now a Honeywell wireless one) is 15.5 while the thermostat is set for 26C (don't actually want it that hot, it would be nice if it could get close ) Radiator in the lounge (only one that's on on the main floor) is warm but not hot) and the radiators upstairs are on (but because they're thermostatically controlled, not roasting hot).

While I was in the loft room listening to the boiler/feeling the pipes, I remembered to test the CO2 alarm

Might be useful if you feel the pipes either side of the silver/metal valve underneath the tank. As piglet John said, it could well be your zone valve is stuck/motor has gone.