Boiler/Central heating pump advice
Discussion
Hive knowledge please.
I've not had the heating on for weeks, however, the hot water goes off at 10, the pump in the airing cupboard continues to run till about 2am (the bloody thing keeps me awake most nights) and the radiator in the bathroom is baking hot most of the time.
What's wrong?
Thanks in advance.
I've not had the heating on for weeks, however, the hot water goes off at 10, the pump in the airing cupboard continues to run till about 2am (the bloody thing keeps me awake most nights) and the radiator in the bathroom is baking hot most of the time.
What's wrong?
Thanks in advance.
If the radiator is hot then it certainly sounds like the boiler is firing. Assuming the system is fully pumped, it sounds very much like the microswitch in the motorised valve is sticking when the valve closes. It's obviously not opening the heating port, so that radiator must be on the primaries.
Dodgy hot water valve.
Dodgy hot water valve.
Slyjoe said:
Hive knowledge please.
.. the hot water goes off at 10, the pump in the airing cupboard continues to run till about 2am
It's a bit odd that it goes off after a few hours - normally when these things are faulty they stay in the faulty condition... the hot water goes off at 10, the pump in the airing cupboard continues to run till about 2am
Also, for hot water only in a fully pumped system, the pump should barely be running - if you use some hot water it'll reheat the cylinder but that should only take a few mins and then the pump goes off again. In other words, you shouldn't notice the pump going off at 10PM as it wouldn't be running unless you've just used some hot water.
What make & model boiler is it?
Arthur Jackson said:
If the boiler isn't firing why is the radiator hot?
Just the one radiator in the bathroom gets really hot when only the water heating side of the system is being used....Deva Link said:
What make & model boiler is it?
Its quite an old "Glow Worm" the last time we got it serviced the Gas man said it was in lovely condition and to never change it for a condenser type unless it was beyond repair, and as its old, parts will eventually be in short supply.Its definitely the pump in the airing cupboard about 4 inches diameter and orange in colour thats running.
Would it be using lots of electric doing this?
Slyjoe said:
Its quite an old "Glow Worm" the last time we got it serviced the Gas man said it was in lovely condition and to never change it for a condenser type unless it was beyond repair, and as its old, parts will eventually be in short supply.
Its definitely the pump in the airing cupboard about 4 inches diameter and orange in colour thats running.
Would it be using lots of electric doing this?
Pump uses about 150watts, so not huge.Its definitely the pump in the airing cupboard about 4 inches diameter and orange in colour thats running.
Would it be using lots of electric doing this?
It would be useful to know the model of the boiler, and if the boiler is still firing now and again while the pump is running (after it's supposed to have turned off).
Lastly, do you know if you've got 2 separate 2 port motorised valves, or just one 3 port valve?
Jonnas said:
I'm no plumber but are you sure that this rad isn't designed to work independently from the rest so you can dry your towels through the summer? My MIL's system does this in each bathroom but I have no idea how they are controlled........
They're often plumbed to get hot when the hot water is on (as AJ points out, plumbed across the primary flow and return so they get hot when either HW or CH are running) but as I said earlier, in a fully pumped system the boiler should only be heating the hot water now and again during the day (basically for a few mins after you've drawn a reasonable qty of hot water). If the rad is getting hot when the system is supposed to be off then that obviously implies the boiler is firing when it shouldn't be. Most obvious cause of that is stuck motorised valve. If it is that then his hot water will likely be furiously hot, especially as he says the bathroom rad is baking hot. It could just be a stuck microswitch in the valve in which case the hot water wouldn't be so hot, but would explain the baking hot bathroom radiator. Or it could be a fault in the boiler, but strikes me as unlikely as it eventually does go off.
It's hard to diagnose these things over the internet as, in the absence of clear information from the OP, we're making guesses about his system.
Deva Link said:
They're often plumbed to get hot when the hot water is on (as AJ points out, plumbed across the primary flow and return so they get hot when either HW or CH are running)
This sounds right for our system, its always been the case.Deva Link said:
but as I said earlier, in a fully pumped system the boiler should only be heating the hot water now and again during the day (basically for a few mins after you've drawn a reasonable qty of hot water).
It sounds like it is working correctly.Deva Link said:
If the rad is getting hot when the system is supposed to be off then that obviously implies the boiler is firing when it shouldn't be.
It isn't Deva Link said:
Most obvious cause of that is stuck motorised valve. If it is that then his hot water will likely be furiously hot, especially as he says the bathroom rad is baking hot.
It seems to be way hotter than it should be, despite me turning the thermostat that is nestled against the immersion tank to 40 degrees.Deva Link said:
It could just be a stuck microswitch in the valve in which case the hot water wouldn't be so hot, but would explain the baking hot bathroom radiator.
Water is fricking hot, as is the rad.Deva Link said:
Or it could be a fault in the boiler, but strikes me as unlikely as it eventually does go off.
I'm sure its not too, Deva Link said:
It's hard to diagnose these things over the internet as, in the absence of clear information from the OP, we're making guesses about his system.
I appreciate that, and thank you for taking the time to reply. The boiler is a "glow worm space saver kfb", the pump I would have no idea if it was a triple or double switched thing, it has one pipe in and one out, the one in is connected to a small white switching box which is attached to the immersion.I guess I just really need to know if this is costing me more than just sleep by not getting someone in ASAP.
We've all seen "rogue traders" and i need a clue at least before I call a boiler dude in to fix it.
Thanks again.
It's got to be a sticking motorised valve - they don't last for ever, and some are noted for being unreliable. One of my neighbours has a sticking 3-port valve but he's content to give it a bang whenever he becomes aware it's stuck. Sometimes operating them manually a few times frees them up, but sounds like yours frees itself up after a while anyway.
Having the pump running isn't costing a fortune, but heating the water to a higher temp than needed will be more costly. It's also hazardous if you have visitors who don't expect it.
Changing them can be a bit of a pain depending on where they are located. System has to be drained down.
Having the pump running isn't costing a fortune, but heating the water to a higher temp than needed will be more costly. It's also hazardous if you have visitors who don't expect it.
Changing them can be a bit of a pain depending on where they are located. System has to be drained down.
t and always stick.Ferg said:
If the valve is sticking the boiler would fire.
Yes - the OP's answers are a bit confusing there. I'm assuming (I know that's dangerous!) that the boiler is firing as he says the water is very hot and turning the cylinder stat down didn't help.It would be useful to know if it's a 2 x 2port valve system or 1 x 3 port valve. If it's a 3 port then without power it should default to the hot water position so if the pump was running on its own without the boiler firing then that would cause the hot water cylinder to cool down.
It could be a boiler fault - like the famous Suprima lock-out which runs the pump all the time, but it has to be reset before it'll do anything else, so the OP saying it eventually clears makes a boiler fault unlikely.
It'll probably turn out to be a chafed wire somewhere!
The timer and stats operate the motor in the zone valve, which opens the valve and hits a microswitch which powers up the boiler.
The microswitch is powered from a permanent live supply (2 ports valves only) which is why the pump and boiler would stay live if the the switch gets stuck.
The microswitch is powered from a permanent live supply (2 ports valves only) which is why the pump and boiler would stay live if the the switch gets stuck.
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