Central Heating and Hot Water Gone!

[MrPooks]

Hi...anyone who can help!

We have recently had problems with our central heating system. We noticed a few weeks ago that our radiators were no longer heating up, apart from the one in our bathroom, so called a local plumber out for a look.

He confirmed that the pump was working (if a little noisy) and we had hot water in our taps so he thought it could be either an air or a sludge problem. He arranged to come back another day to drain the system so that he could learn a bit more and duly did so. Unfortunately after doing this he thought he may have moved some dirt as the boiler was no longer getting hot water up to our tank in a cupboard in the bathroom.

He said to leave it for a few days then try firing it up again in the hope that any air may have worked it's way out but that we shouldn't hold our breath. He also said that his recommendation was for a new system so I asked him to do us a quote for various options. That was last week and is the last we've heard from him. To his credit he's not charged us for either of his visits but I am also getting the impression that he doesn't want the job of sorting us out as I've tried 'phoning him on numerous occasions and he's not taking the calls.

Also, last weekend, I drained the system myself and added some X400 sludge buster before refilling (following good instructions) but so far this has had no effect.

So our current situation is as follows:

No heat to radiators except bathroom
No heat to hot water tank
Boiler (non combi: Halstead Best 50) fires up OK but as soon as water has reached temp it shuts itself down (I think you can hear the water heat, then boil, then boiler switches off and you hear the water drain back?)

I am trying to get a handle on options of what's likely to be the cause before getting another plumber in. I've read that we should be OK with our microbore pipes, system-wise, but don't know if a power flush would sort it out, or if we need a new boiler - if so fine, we're just a bit frustrated at being left high and dry.

I hope that someone out there can offer some advice

Thanks in advance

Andy

 

[solman]

providing the pump is running and there is water in the system it sounds like a possible heat exchanger with the info you have provided

 

[jackthom]

For the sludge buster to have an effect there needs to be at least some flow of hot water through the system to start with.

If the pump is not already on max speed you could try increasing it.

You don't say whether there is a motorised diverter valve or zone valves installed.

If it can't be done with a zone valve can you experiment with closing all radiators to see if the pipe run to the hot water cylinder can be forced to get going? Assuming it is part of the pumped system.

You could do something similar with individual radiators on by themselves and if possible with the path through the hot water cylinder shut.


Frankly I would still also suspect the pump a little bit, until I had tried a replacement.

 

[rojaca]

Can you describe what controls etc you have in airing cupboard, motorised valves, air vents and where your pump is situated. I am suspecting by description you may have gravity DHW and rad in bath was heat leak.
I'm suspecting an airlock or blockage but some more info would be handy.

 

[rojaca]

BTW plumber not answering your call is looking like it may a blessing after your description of events

 

[bengasman]

Your problem is probably down to a combination of a number of things.
Airlock
Sludge
Worn pump due to sludge.
If there is not water in the pump, the pump won't work; this is the first thing to check, see faq.
If there is water in the pump, but the pump is barely working, it won't go round either; test the working of the pump, see faq.
If the pump is still good enough, and has water in it, you are looking at sludge, or an airlock.
Try running dhw only, the cylinder is usually less effected by sludge than the rads.
For the cleaner to work, there has to be some heat, and some flow; without this, it will do very little.

The chap you had over to look at the system, clearly was not very good; the chances a new boiler would solve the problem are decidedly slim.

 

[electronicsuk]

Could it be as simple as a stuck CH zone valve? It's not at all uncommon for bathroom rads in older houses to be wired independently of the CH/HW zones, which would explain it being the one room in the house with working heating. It would also account for the cycling/ketting of the boiler, as it's unlikely the heat load of a single radiator will be enough to keep this from happening.

 

[tincup]

Hi

Sounds like a blockage on return to boiler.
Is the return pipe at the boiler getting hot?

HTH

 

[MrPooks]

Hi

First off, thanks to all who have got in touch so quickly

A bit more info on our system:

In the hot water tank in bathroom the only control (aside from the timer, which does not have the facility to choose hot water only - all or nothing, CH usually controlled by zeroing our thermostat in the hall) is a thermostat strapped to the tank

The pump is under the floor in our bedroom, along with the control valve. I think the plumber who came in checked that as he had me downstairs turning the thermostat up and down a few times - I think he was making sure the valve switched over.

Our pump is working but q bit noisy; plumber said it's OK but may be on the way out...

When the boiler fires up, we get pipe noises in our bedroom (expansion and banging) as if the water is getting somewhere...

I'll have a play (gulp!) this weekend to have a look at the pump and will experiment with turning rads and cylinder feeds off to see about kick starting it.

Maybe also 'it it wiv an 'ammer! (A rubber one of course)

Thanks again for your guidance - any further thoughts would of course be most welcome

Cheers

Andy