Boiler constantly on

[Toes]

I installed a new hive system a couple of months ago as the old programmer started to give problems , all was working well until yesterday.
The central heating seems to be constantly on .
Would this be down to a stuck valve or something else ?

 

[stem]

It could be. Motorised valves do have a microswitch inside that is triggered by the valve when the central heating is on. These micro switches have been known to stick 'on'.

Unfortunately though this fault can have quite a few other causes, some obscure. For example; If the radiator in the room where the Hive thermostat is located has a thermostatic radiator valve fitted, that can prevent the Hive reaching its set temperature, so the boiler stays on.

You don't give us any information about your system, but if you have a hot water cylinder, the thermostat on than can fail, or be disturbed from its correct position and keep the boiler going. [That wouldn't keep the radiators on as you suspect they are though]

It is an electrical fault, for someone who is electrically competent, understands circuits and can use a multimeter then it isn't too difficult to trace the switched live supply to the boiler back through the various components to find the culprit.

The central heating seems to be constantly on

I'm puzzled a bit by this. Is it. or isn't it? Could it just be the case that it seems to be on more recently now the weather has cooled and your home needs more heating? or is it really constantly on so that your house, (or or if you have TRV's, the rooms without them) is far too hot and operating in the middle of the night when it should be off.

 

[Toes]

It is on all the time even when the stat says it is above the set temperature. It is a combi boiler .

I suspect it will be a valve will check them

 

[stem]

Ah, OK if it's a combi boiler, then normally they don't have a motorised valve with a microswitch in unless you have two or more heating zones. They look like something this and are external to the boiler.

Untitled

• stem
• 26 Mar 2010
• 6

May be a fault with the Hive or the boiler, in which case I'm sorry but can't help you, you will need the help of a gas safe engineer, but the first question they will ask is what make / model of boiler you have.

 

[Toes]

It’s an oil combi camray 5 ,
I’m starting to think I may have the wrong hive receiver should have a single where I have a dual . Doesn’t explain why it has been working until now though

 

[Toes]

E6B0514B-C950-4449-8226-1985351DF1C0

• Toes
• 10 Nov 2017

Can the dual be used if so in what wiring state

 

[oilboffin]

With the camray a common fault is the diverter valve actuator it could be sending a signal to keep the boiler running.Bob

 

[stem]

It’s an oil combi camray 5 ,
I’m starting to think I may have the wrong hive receiver should have a single where I have a dual . Doesn’t explain why it has been working until now though

The wiring of your Hive shows a connection has been made to the hot water control terminal (Brown wire, terminal 3) so both channels of the Hive are being used for something. Nice installation with the cable ferrules too!

I'm not very familiar with oil boilers, as the two guys I used to assist regularly are Gas Safe, so I didn't see oils boilers much. However if your boiler has a pre-heat facility, or some internal storage of hot water that has the facility for external control, then the dual channel Hive would be correct. If so, I would have expected that you will have set the timings for it, so would know what it's doing.

Regarding your fault, I would put my money's on oilboffin's post, he's usually spot on.

 

[oilboffin]

Thanks for that stem I'm impressed by your knowledge and honestly too.Bob

 

[Toes]

I think it is the actuator and the valve , I loosened the valve off as it was a bit stiff but the actuator is struggling. It is now operating as it should just slow to react . New valve and actuator on order .
Thanks for your help