Boiler coming on by itself

[redapple]

Hi Got a Greenstar FS (Floor Standing) 30CDi. Its programmed to come on in the evening 6-7pm Hot water only. But is now coming on by itself for hot water. It was working fine before no problems. The two valve Honeywell V4043H1056 (272848) which connects to the hot water tank makes a buzzing sound and I believe is the cause of the problem. I was planning on replacing the head . As it opens and closes no problems Before doing this I was wondering if anyone has ever come across this problem and if they found it to be something else? should I be placing the whole valve Thanks

 

[Howsie]

I doubt the valve is the problem if the timer isn't on.

 

[R1CKY]

Disagree Howsie, the microswitch inside the valve is live regardless of what state the timer is in. Could be a sticky microswitch inside the valve. Is the valve actually open when its firing itself up? The lever should move freely side to side when the valve is in the open position.

 

[redapple]

Disagree Howsie, the microswitch inside the valve is live regardless of what state the timer is in. Could be a sticky microswitch inside the valve. Is the valve actually open when its firing itself up? The lever should move freely side to side when the valve is in the open position.

Hi Yes when the valve opens up, lever moves freely. any idea how to unstick the microswitch? someone else told me that it could possibly be the the valve spindle which is stuck?. System is clean, was flushed and inhibited not too long ago and has a filter on it.

 

[Nostrum]

You need to test to see if the valve is being powered open or not. This will tell you whether or not it is the valve or other controls at fault.

 

[redapple]

You need to test to see if the valve is being powered open or not. This will tell you whether or not it is the valve or other controls at fault.

hi Programmer can open it up and close it , the timer also works. No problem with the other valves on the system. The valve also makes a buzzing sound when in operation(opened)

 

[jtsplumbing]

Depending on age I change the complete valve, it could be the body that is at fault (Sticking)

 

[Howsie]

Disagree Howsie, the microswitch inside the valve is live regardless of what state the timer is in. Could be a sticky microswitch inside the valve. Is the valve actually open when its firing itself up? The lever should move freely side to side when the valve is in the open position.

Perhaps but I can't see a sticky micro switch turning it ON at odd times.

 

[kirkgas]

I doubt the valve is the problem if the timer isn't on.

If the timer is off it's 99% likely the fault is the zone valve, if its not closing it will allow power to fire the boiler

 

[stevetheplumber]

next time its running when it shouldnt be check for 240 on the brown wire if its powered then the fault is elsewhere

 

[Dotty]

next time its running when it shouldnt be check for 240 on the brown wire if its powered then the fault is elsewhere

I agree, have you just replaced anything?