No-one can work out why our heating isn't working!

[bttone]

You say you have an immersion heater, so I'm guessing you are on an open vented old style system.
If upstairs works and downstairs doesn't then the first thing most plumbers would look at is the pump.
Your hot water cylinder will be upstairs so will get heat, but without the pump working it will take a lot longer than usual because the boiler will only be running in short bursts due to overheating as the pump isn't dispersing the heat.
All downstairs valves aren't going to block at the same time.
A system clean doesn't have to be done in the summer, whoever told you that was either lying or doesn't have a clue.
Where did you get your 'plumbers' from?

I would agree it's the pump ,and I'm no plumber ,it would benefit from a flush with fernox too ,you can check your pump operation by undoing the slot head bung at the front of the pump ,to see if it's moving ,also try turning the pump speed up ,you should have 2 or 3 speeds ..but if this doesn't improve things ,maybe the vaines in the pump are shot ,so new pump tine

 

[jtsplumbing]

And make sure the Pump is facing the right direction

 

[jtsplumbing]

I would agree it's the pump ,and I'm no plumber ,it would benefit from a flush with fernox too ,you can check your pump operation by undoing the slot head bung at the front of the pump ,to see if it's moving ,also try turning the pump speed up ,you should have 2 or 3 speeds ..but if this doesn't improve things ,maybe the vaines in the pump are shot ,so new pump tine

Looking at photo pump seems to be on max speed

 

[Zippymark]

To be honest though if a pump has only lasted 5 years there's probably another problem too, even if a new pump got it going. I had one recently where like yours, only some rads were heating up and they didn't have as much hot water as before. The pump was still spinning but with no real force, I put a new one in and it still didn't heat everything up, and the pump just didn't sound right. I spent ages trying to get air out but it ended up that the 30 odd year old boiler was so full of sludge that it was slowing everything down. A powerflush sorted it. My guess is just running a cleaner through and draining wouldn't have, you need the force of a powerflush to lift all the sludge out.

 

[dan_the_plumber]

I’m suprised no one has suggested that the pump may have been fitted the wrong way around. Or that the flow and return might be plumbed the wrong way around onto the boiler. Or that the pump setting might be too low. Or that the system might not be correctly balanced. Or that the bypass might be wide open. Or that there might be air trapped in the System.

 

[Dave14]

I would replace old gate valves, I have known them to stick ... from the outside they seem fine but the internal thread has gone.

 

[jtsplumbing]

I’m suprised no one has suggested that the pump may have been fitted the wrong way around. Or that the flow and return might be plumbed the wrong way around onto the boiler. Or that the pump setting might be too low. Or that the system might not be correctly balanced. Or that the bypass might be wide open. Or that there might be air trapped in the System.

Come on Dan ! read all the replies I did ask if pump was the right way round, look at the photo pump is set to max speed

 

[Mick Bonner]

How about balancing the system? Drain and see what comes out? If got TRV, on wrong way, how old is the system?

 

[kentplumbing]

I am currently huddled by a fan heater. Our heating hasn't worked properly for over 3 weeks despite visits by 2 plumbers, a lot of beard-stroking and twiddling of valves.
The T37HW-3 Zone Programmer seems to be working fine. The boiler fires up enthusiastically when the timer clicks in, and there the problem starts.
The hot water DID heat up- this seems to have fizzled out in the past 2 days and we have to use the immersion heater. The upstairs radiators heat up, but the downstairs don't, UNLESS you turn off the upstairs radiators AND the hot water. Then you get adequate heat in one or two radiators, always in the same sequence. If the heating is boosted to stay on for about 4 hours, three and a half radiators will warm up eventually.
The Blokes have tried out unblocking radiator valves; have suggested the system needs flushing out (apparently can't be done till the summer?) Other than that, theres been a lot of shrugging.
It seems to me that somehow there's not enough pressure shoving the heat round the system. Could it be a pump? I have NO IDEA how any odd this works but I am sick of freezing and listening to said Blokes talking rubbish. I would LOVE to be able to tell plumber no 3 (coming on Friday) what the problem is!

Sorry , but Its The Pump.

 

[Gasinspect]

Have seen blocked feed from loft tank, do you get a good stream of water coming out when you bleed upstairs radiators? Some power flushes don't include loft tank -!

 

[Gasinspect]

Another thought- sent hours on simisim problpr, did flush but couldn't get good flow through system, found a y-filter covered by a more recent fitted kitchen cupboards where they had hidden pipework. Blocked solid and reverse flow of flushing had probably made it worse. Customer had mixed feelings about work to make good, which I understood but thought unfair on us. But piping hot system after clearing it. Suggested a magnaclean.

 

[Ric2013]

If that's a new pump, it would seem to be a reasonable assumption to make at this distance that the problem is not the pump. Unless the new one is also faulty, which is rather unlikely.

OP - Am I right to assume that the system worked well before 3 weeks ago?

 

[sammathias]

I’m suprised no one has suggested that the pump may have been fitted the wrong way around. Or that the flow and return might be plumbed the wrong way around onto the boiler. Or that the pump setting might be too low. Or that the system might not be correctly balanced. Or that the bypass might be wide open. Or that there might be air trapped in the System.

Well given that the system has been working and has just stopped working without any plumbing work being undertaken would suggest that most if not all the things you are suggesting is unnessesary.