Heating not working, but hot water is - Help, cold baby!

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Hi Guys,

I'm going to phone Potterton tomorrow morning to try to get an engineer to to try to repair this, but in the mean time, could any one offer any advice please, as my house is freezing, and I've got a baby to try to keep warm.

The heating and hot water has been working fine all day, but this evening I have tried to boost the heating for an hour, and it isn't coming on.

The hot water heating is working fine, as I have just ran that on boost for 15 mins.

I have Hive, and the correct lights etc are coming on the controller, and this seems like it is working normally, so I am thinking it is the boiler.

When Hive is telling the boiler it is required, I have checked the circulation pump in the airing cupboard, and there is no 240v to this - but I'm unsure at this stage if the boiler is requesting the pump to start or not?

Is there any more basic checks I can do please? Is there a hot water/heating diverter valve I can check etc?



Any advice would be greatly appreciated.


Thanks a lot
 
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There is also a Danfoss HPA 2 slightly down from the pump, which possibly diverts from the hot water tank to the central heating? I presume this should have a voltage on it?

Edit: I see you can manually actuate the Danfoss valve - doing this doesn't seem to help, so I think it is related to the boiler?
 
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What's the boiler you have? The hive receiver at the boiler does the green light come on for heating when you make a demand?
 
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What boiler do you have? it is a combi? Check for any tripped fuses, If boiler has pressure gauge check that its not 0 psi. Have you tried to power off the boiler and back on just in case? Is the set point of the thermostat higher than the room temp? Just few little things to check in the mean time.
 
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H,

It is a Potterton Promax HE.

Yes, the green light comes on fine for both heating and water. The hive receiver makes it normal quiet click shortly after the green light is on.
 
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What boiler do you have? it is a combi? Check for any tripped fuses, If boiler has pressure gauge check that its not 0 psi. Have you tried to power off the boiler and back on just in case? Is the set point of the thermostat higher than the room temp? Just few little things to check in the mean time.

Hi,
- It is a Potterton Promax HE
- My system is an unvented water tank type, and the boiler heats both the water tank and central heating. Water is OK, and the boiler fires. Heating doesn't.
- I've tried resetting and powering off the boiler and whole hive system
- Water pressure on the heating side is about 1 bar. No gauges on the boiler.
- Heating set point has been at a few different temps, 2 degrees higher than the room, up to 10 degrees higher



Thanks a lot
 
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UPDATE

Manually actuating the Danfoss valve does bring the heating on (I had the boiler turned off when I was trying it just before).

So the heating is on, but with the Danfoss valve in a locked open position?!

I guess this is controlled from the boiler? If you move the lever from the locked open position, it automatically goes back in to the water heating position.
 
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Is it dangerous leaving it locked open? It is on the water pipe side, nothing to do with gas.

I guess I just won't have hot water now? Which we can plan around.
 
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No nothing dangerous and your water should heat aswell, any local engineer will have it fixed in no time
 
D

Doggit

It should be okay to leave the lever in the open position. I've no experience of Hive, but as the boiler comes on for the hot water, and still works when you move the lever manually, then your boiler is okay. If you need to reheat the hot water tank, then just release the lever, and the controls should take over till the hot water tanks full.

Some of the Hive experts here may be able to guide you through the problem later, but I think you're okay for now.
 
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Hi Guys,

Thank you for all the replies. We had a warm house through the night as least :)

Could this valve not be being told to operate from the boiler itself? Or could the valve be knackered and isn't operating electrically?

Also, to check Hive isn't the problem, I could just link out the terminals across L and #4 couldn't I, as then the heating would be called for all the time and see if that worked? Thermostat wiring is linked out already, as Hive controls that. I don't think it is Hive to be honest, but obviously this needs ruling out.





Thanks a lot
 
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Its the motorised valve which tells the boiler when to operate depending on the input its getting from the system controls. Sort the motorised valve and all should return to normal.
 
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The boiler doesn't tell the valve to work, the valve tells the boiler. Sequence is:

1. If programmer in a heating period. THEN
2. If thermostat says heat is needed. THEN
3. Thermostat switches power to valve. Valve opens. THEN
4. Valve switches power to boiler switched live terminal. THEN
5. Boiler fires.
 
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If there is power to the white wire on the valve when the heating is on, then it is likely the valve head needs a new motor.
 

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