Boiler keeps on boiling water even heating is switched off

[John.g]

Yes yes yes, you are right, if I touch it, then power is back on！！！

OK then that's your problem then, just confirm that the CH and HW are both off??

 

[luckyvictor]

Did you put any demands on?

No, but if you are referring to my power issue earlier, I have power only when I reconnect the orange wire back to system

 

[luckyvictor]

OK then that's your problem then, just confirm that the CH and HW are both off??

What?? It itself is a problem???

I have now connected the orange wire back and measured at WC between orange and blue/neutral or yellow/green earth, both showing 240v

And I did it with boiler on, program for both CH HW off.

 

[John.g]

Yes, that is the problem, IE your M.valve is still sending a signal to the boiler/pump to run even though he M valve isn't getting a demand to open from the relevant system so needs renewing, more than likely just the actuator which doesn't involve draining down the system.

Why didnt you probe between the removed orange wire and earth with power on but both CH & HW off, it should have read 230V.

 

[luckyvictor]

I agree with you conclusion, but base on the fact that this lever is loose.

Still trying to understand how my system is not powered up without having it to reconnect back.

I am thinking to replace the synchron motor, which I have learnt how to from youtube, seems like an easy job, and yes, no draining system need, although it is a challenge for me as you may see from my earlier photos, the faulty one is the one below and i can't even remove the housing completely.

Did a quick search on google for price and availability, what would be the difference between the 20 quids one from screwfix and 10 quids one from amazon? which one is a safe/wise choice?

 

[John.g]

Have never replaced the motor only.

"Still trying to understand how my system is not powered up without having it to reconnect back."
If you mean boiler/pump not running then its because there is no demand because you had removed the orange wire from the faulty M.valve, if you leave it disconnected and create a CH or HW demand then the boiler/pump will start up, is it a CH or HW M.valve thats faulty?.

 

[luckyvictor]

Yes, that is the problem, IE your M.valve is still sending a signal to the boiler/pump to run even though he M valve isn't getting a demand to open from the relevant system so needs renewing, more than likely just the actuator which doesn't involve draining down the system.

Why didnt you probe between the removed orange wire and earth with power on but both CH & HW off, it should have read 230V.

Sorry, I did that, so i did measure 240V between the removed orange and the earth/neutral, while the connected orange in the box are reading 0V.

I was too focusing on why I cant turn on the system even though i had turn power on...

 

[luckyvictor]

Have never replaced the motor only.

"Still trying to understand how my system is not powered up without having it to reconnect back."
If you mean boiler/pump not running then its because there is no demand because you had removed the orange wire from the faulty M.valve, if you leave it disconnected and create a CH or HW demand then the boiler/pump will start up, is it a CH or HW M.valve thats faulty?.

I get it now!!!!!

Thank you for being so patient to me!!!!!

Yes, I thought there were no power in the system, as I thought the green indicator on the pump means it is working/standby. I just disconnected the suspected orange wire again, turn on the system, boost hot water from the programmer to create demand, and boiler wakes up to work!

 

[luckyvictor]

so I have swapped the synchron motor from a good one to the faulty one, it does not seem to help with the voltage, it still registers 240V.

So I need to replace the whole M. Valves?

 

[Deleted member 120897]

so I have swapped the synchron motor from a good one to the faulty one, it does not seem to help with the voltage, it still registers 240V.

So I need to replace the whole M. Valves?

Yes, it’s not the motor at fault, it’s a microswitch.