Boiler keeps on boiling water even heating is switched off

[luckyvictor]

The problem is, my ideal boiler logic heat h15 keeps on burning (igniting flame icon on) all the time, all day long, regardless of the programmed on off schedule for both heating and hot water.

when we have the heating turned off from the thermostat programmer (danfoss tp9000ma-si), i.e frosted protection at 5 degree, or it is "off" during the daily program. It still burning, heating water.

When we have both heating and water hot scheduled to be off, it still burning.

I can safely say that there is no demand called from the program and it just supplies. The temperature displayed on the boiler is always 70+, I expect it displays 00 sometimes to show no demand required.

I have had an engineer check when doing annual service, boiler itself is ok, but he doesn't know what this problem is, suggested is the motorized valve, but he can't prove it is not functioning, as he seems to prove that all 3 of them are working ( 2 heat zone, 1 hot water).

So any suggestions to my problem please? How may I track down the root cause and take action accordingly?

Right now the house is always burning hot, I have to manually adjust the radiator thermostat, as well as switch off the boiler itself to avoid unnecessary heat(money)

 

[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.

 

[John.g]

The whole actuator, at least, , as its the spring return thats probably causing the problem or the end switch sticking on, remove the actuator from the valve and switch the zone valve on off with the actuator removed and see if 230v still present when switched off, also open/close the zone valve with a adjustable spanner or such on the valve spindle, it should move relatively very easily.

 

[luckyvictor]

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

which/where is this microswitch please? can it be replaced on its own?

 

[luckyvictor]

The whole actuator, at least, , as its the spring return thats probably causing the problem or the end switch sticking on, remove the actuator from the valve and switch the zone valve on off with the actuator removed and see if 230v still present when switched off, also open/close the zone valve with a adjustable spanner or such on the valve spindle, it should move relatively very easily.

Would like to try, but did a search on youtube, couldn't find any tutorial of how to, basically i have no idea what the structure is.

You know any good youtube video i can follow please?

 

[Deleted member 120897]

which/where is this microswitch please? can it be replaced on its own?

It’s where the orange wire connects, but probably best to renew the actuator (valve head), some have replaced them, but I wouldn’t know how as I’ve never done it.

 

[Deleted member 120897]

Would like to try, but did a search on youtube, couldn't find any tutorial of how to, basically i have no idea what the structure is.

You know any good youtube video i can follow please?

 

[luckyvictor]

Thanks, now i know what to expect to see. will try it sometimes next week.

 

[ShaunCorbs]

Have you tested if theres 240 on the brown for the 2 port valve in the wiring centre ?

With nothing calling eg heat and hot water timers off

You won’t get the head off as there’s not enough space to lift it out need to rotate the valve so the head sticks out front time for a plumber I would say

 

[Deleted member 120897]

You won’t get the head off as there’s not enough space to lift it out need to rotate the valve so the head sticks out front time for a plumber I would say

Spoilsport!

 

[luckyvictor]

Now something I don't understand, I thought the system is actually running, but even though I boosted hot water, create demand, the boiler is not on, is always 00, I have only removed the faulty orange wire from WC, and touched absolutely nothing regarding HW, and I did see the boiler ignited yesterday for once (didn't check after), the time that I thought the system had no power.

So what is my problem now ...

When I press restart from the boiler, it doesn't seem to go through the usual start up sequence, but stays 00 all time...

 

[Deleted member 120897]

Are thermostat’s up? Could be already satisfied.

 

[luckyvictor]

Are thermostat’s up? Could be already satisfied.

But I asked for hot water as well, shouldnt I see it fires for a second at least?

And the start up sequence doesn't seem to do anything.

 

[John.g]

If neither the roomstat or the cylinder stat is calling for water then boiler wont start, either boost the HW and turn the cylinder stat (the one attached to the cylinder) up to start the boiler or just hold your trusty orange wire up against the common terminal again to (see) the boiler firing.

 

[Deleted member 120897]

But I asked for hot water as well, shouldnt I see it fires for a second at least?

And the start up sequence doesn't seem to do anything.

Not if the cylinder is already satisfied, and you have it set low at 45 degrees.