Hot water off at programmer but cylinder boiling hot?

[candg]

I fitted new boiler with new motorised valves. Cylinder is boiling hot even tho motorised valve is shut. Cylinder flow hot

 

[OwainDIYer]

motorised valve stuck or miswired.

short circuit or miswire in wiring centre.

cylinder stat miswired or not making thermal contact with cylinder.

 

[candg]

I had the electrician that wired it back and he says it's not the wiring. I'm going to take valve of and have a look to see if it is stuck. Cylinders next to boiler in attic so is the valves so moved bypass pipe down return line thought it might have been circulating around cylinder but still nothing. If the motorised valve is opening when you put it to on and shutting when you turn it off at programer does that mean it's ok?

 

[OwainDIYer]

not necessarily, you have to check it's actuating the microswitch inside.

 

[maltaron]

If it is a three port valve if I remember correctly it defaults to hot water only with no power, but the boiler should not be on. I believe the boiler is switched by the programmer for hot water only, or HW and CH, and by the valve contacts for central heating only. If it is S-plan(independent 2 way valves) The boiler is normally switched by the motor contacts.

 

[Whitespirit66]

Is the hw heating up on it's own (ie. boiler on when it should be off) or when the ch is on?

 

[candg]

Thanks for reply guys I'm going back on Thursday to check valve and to see if it's firing up itself. I don't think it fires itself it's passing through the valve when it should be off.

 

[dreadnoughtheating]

I fitted new boiler with new motorised valves. Cylinder is boiling hot even tho motorised valve is shut. Cylinder flow hot

If you are GasSafe Registered, join the Combustion Chamber, there you may become privy to some more ideas as to why this happening.

DH

 

[candg]

I got new motorised valve head and body. Drained down took valve off long bit of solder stuck in valve stopping flappy valve to close ! so just changed it to ball valve motorised valve. Works perfect Thanks for help guys much appreciated.