Boiler won't turn off

CrazyFather1 · 11-01-2021 11:35pm #1

I have standard oil boiler, I have noticed every so often over the last while it sometimes doesn't shut down. Not it is constantly running.
See image attached. This is like system board for heating.
You have 1 and 2 written on them. This is when heating is on and you have both on. Now if I turn off heating then number 1 goes off but number 2 stays on.
I have two automatic controllers which are connected to thermostats. One for heating and one for hot water

Does this mean the automatic valve for the hot water is gone bang?

CrazyFather1 · 14-01-2021 10:17am

Sorry anyone give me an idea/ Thanks

John.G · 14-01-2021 10:30am

Don't know what your picture is showing but you should have a motorized valve each on the HW and the CH flow pipes, these when opened give the run signal to the boiler and when they close shut down the boiler but sometimes the switches on the actuator heads give trouble and don't trip the boiler. See if you have these and post a pic. Maybe these are the "automatic controllers" you refer to.

CrazyFather1 · 14-01-2021 12:21pm

John.G wrote: »

Don't know what your picture is showing but you should have a motorized valve each on the HW and the CH flow pipes, these when opened give the run signal to the boiler and when they close shut down the boiler but sometimes the switches on the actuator heads give trouble and don't trip the boiler. See if you have these and post a pic. Maybe these are the "automatic controllers" you refer to.

Thanks

I have two automatic values which are connected back to these two electrically units. When I turn on heating the amber lights turn on and then you can hear the automatic valve open. That is number 1

On number 2 its the same. But now when I turn off, you hear the valve close but the light doesn't go off and the boiler keeps going.
Would this suggest the valve is broken? or something wrong with the heating controls?
The automatic valve is just a white box with Sunvic wrote on it, then Hot water scribbled with pencil on it

John.G · 14-01-2021 12:26pm

Yes, that looks like a mot. valve, get the valve to close then you will/should see a lever, you should feel a fair resistance when moving this slowly, if not then definitely a problem but even if there is resistance it still points to a actuator problem, if you have a multimeter or even a phase tester, can tell you where to test for voltage.

CrazyFather1 · 17-01-2021 10:48am

Thanks for help, got a chance this morning to take the motorised valve apart.

Pic attached

Thanks again

John.G · 17-01-2021 3:07pm

Switch off the HW (switch 2) .
Follow the cable back to the first junction box or wiring centre there will be a brown and blue wire and a grey and orange wire from that mot. valve, if you have multimeter put it on AC volts and check between brown and blue and it should read 0 volts, if it does read zero volts then check between grey and blue and you should read 230V and between orange and earth 0 volts. If only a a phase tester then "no light" when placed on brown wire, if "no light" then "light" on grey wire but no light on orange wire.

meercat · 18-01-2021 5:23pm

If possible remove the motorised head unit from the pipe work.
You should see a brass spindle that you can twist to make sure the valve is functioning correctly. You may need a small pliers for this but don’t force it too hard.
If everything is moving freely then refit the motorised head unit

K.Flyer · 18-01-2021 6:39pm

Older Sunvic and Myson zone valves do tend to get a but sticky on the actual valve.
As Meerkat says, give the spindle on the brass valve a few twists and free it up first before venturing further.

CrazyFather1 · 18-01-2021 7:56pm

meercat wrote: »

If possible remove the motorised head unit from the pipe work.
You should see a brass spindle that you can twist to make sure the valve is functioning correctly. You may need a small pliers for this but don’t force it too hard.
If everything is moving freely then refit the motorised head unit

Yes have done that and it is moving. I can twist it just using my fingers

CoBo55 · 18-01-2021 7:59pm

Froststat overriding everything?

meercat · 18-01-2021 9:04pm

With the motorised value removed turn power on and off to see does the slot that lines up with the spindle rotate

John.G · 18-01-2021 9:36pm

IMO (obviously) it is far easier to check for power as I suggested above, if anyone is familiar with those sunvic actuators then they should know what triggers the light, if its like the myson I'm fairly sure it's a request to open the valve and not any feed back from the end switch?.

I am 99% sure that the actuator light lights up on a EPH actuator with the request to open so possibly/probably nothing wrong with that actuator, problem somewhere else.

vurstflavor · 18-01-2021 9:38pm

Have you changed battery in thermostat

CrazyFather1 · 18-01-2021 10:07pm

John.G wrote: »

IMO (obviously) it is far easier to check for power as I suggested above, if anyone is familiar with those sunvic actuators then they should know what triggers the light, if its like the myson I'm fairly sure it's a request to open the valve and not any feed back from the end switch?.

I am 99% sure that the actuator light lights up on a EPH actuator with the request to open so possibly/probably nothing wrong with that actuator, problem somewhere else.

Light comes on and light goes off.
Same on both motorised valves.
Boiler keeps going and the pumps keep going.

John.G · 18-01-2021 10:51pm

OK, I thought you said that one light was not going out, so... with both lights off (if no multimeter) simply remove the orange wire from each actuator in turn, the boiler/pump should then stop when orange wire removed from faulty actuator.

CrazyFather1 · 18-01-2021 11:38pm

John.G wrote: »

OK, I thought you said that one light was not going out, so... with both lights off (if no multimeter) simply remove the orange wire from each actuator in turn, the boiler/pump should then stop when orange wire removed from faulty actuator.

Sorry on the motorised valve the light goes off. On the electrical fuses, in the OP I have picture the light stays on. Sorry for confusion

Thanks I have a multimeter. I will try removing the orange and thanks for all the help

John.G · 18-01-2021 11:43pm

Just check for voltage between orange and neutral (blue wire) or between orange and earth.

K.Flyer · 19-01-2021 12:51am

CrazyFather1 wrote: »

Sorry on the motorised valve the light goes off. On the electrical fuses, in the OP I have picture the light stays on. Sorry for confusion

Thanks I have a multimeter. I will try removing the orange and thanks for all the help

The Sunvic valves are grand until they get a bit worn, then the actuators start to go awry.
The secondary switching (orange and grey) may be stuck
Turn off the power, follow the actuator cable back to wherever it is wired into, find the orange and grey, note their location, remove both of them from the connections and using your multimeter check for continuity across the orange and grey, there shouldn't be any.
Go one step further and leave both orange and grey disconnected from their connection block, restore power and use the timer to call for heat, when the actuator has finished rotating check orange and grey again to make sure you now have continuity and check for no continuity again when timer is turned off.
If all of that is in order Power Off and replace orange and grey wires to their respective connections.

You say the boiler keeps running.
When it does, are radiators heating up, or are the pipes going into the hot water cylinder heating up?
Or neither.

CrazyFather1 · 19-01-2021 10:07am

vurstflavor wrote: »

Have you changed battery in thermostat

The wall thermostats are standard ones, they don't have a battery in them that I can find

John.G · 19-01-2021 11:40am

Why not use theM.meter as suggested, brown to neutral 0 volts, grey to neutral 230v, orange to neutral 0 volts. No need to disconnect anything.

Wearb · 19-01-2021 12:36pm

John.G wrote: »

Why not use theM.meter as suggested, brown to neutral 0 volts, grey to neutral 230v, orange to neutral 0 volts. No need to disconnect anything.

Perhaps I haven't thought this out fully, but if another zone was calling, would there be voltage both auxiliary contact wires of the idle thermostat?

John.G · 19-01-2021 12:53pm

Yes. but I am talking about testing/trouble shooting with all zones not calling for heat.
There is all ways a permanent live to the one side of the (volt free) auxiliary contacts, grey wire, the same permanent supply can go to multiple zone valves. With a call for heat via any zone valve, then the brown wire becomes live and the motor operates and opens the valve, the auxiliary contacts, also called the end switch then closes and you now have (switched) live on the orange wire, via the grey wire, which fires up the boiler, so yes, if any zone valve is opened then you will have a back feed to all the other orange wires. I have tested numerous neighbors valves this way (no disconnect with all zones off) and generally find that the contacts are still made so actuator renewal solves the problem in 99% of cases.

In the above case there may be (some fault) something calling for heat so thats why you test brown to N, 0V, grey to N, 230V and orange to N, 0V.

Wearb · 19-01-2021 1:22pm

I was thinking of welded contacts on one valve causing voltage on contacts of idle valve, therefore creating the need to disconnect in the wiring centre (junction box) to properly diagnose the idle one.

meercat · 19-01-2021 2:09pm

Wearb wrote: »

I was thinking of welded contacts on one valve causing voltage on contacts of idle valve, therefore creating the need to disconnect in the wiring centre (junction box) to properly diagnose the idle one.

That’s what I’d do too.

John.G · 19-01-2021 2:29pm

Consider a system with 3 zones, upstairs, downstairs and HW,
with system off, HW is still heating, I then check orange to N, (admittedly, I could check any orange) if 230V then because the HW is still heating, I would disconnect this wire and check that boiler is off , I have never yet come across a case of welded contacts with the valve still fully shut, if this is/was the case then every orange wire must be disconnected until the culprit is identified. I would all ways first check the brown to N in case of spurious signal to open actuator with no fault on the actuator.

Wearb · 19-01-2021 2:33pm

With welded contacts and no call for heat, will the valve not happily close, unaware of the state of the switching contacts?

K.Flyer · 19-01-2021 2:37pm

Wearb wrote: »

I was thinking of welded contacts on one valve causing voltage on contacts of idle valve, therefore creating the need to disconnect in the wiring centre (junction box) to properly diagnose the idle one.

meercat wrote: »

That’s what I’d do too.

Disconnecting grey and orange from the wiring centre really is the best way to establish if the aux switching is functioning correctly.
We know voltage is getting around somewhere, but a quick check on the aux switching as earlier described removes the need to strip down actuators and done properly its done with no power in them.
In the picture of first post it shows a set of relays, it's quite possible that it's a faulty relay staying stuck on.
If the op answers the question if rads or coil are still heating it would help figure where the problem might be.
If both aux switches are fine next thing is to check if the relays are the cause.

John.G · 19-01-2021 2:49pm

This is becoming a bit of a saga all right, I'm glad I use Honeywell actuators which never give trouble!.

K.Flyer · 19-01-2021 3:08pm

John.G wrote: »

This is becoming a bit of a saga all right, I'm glad I use Honeywell actuators which never give trouble!.

It's as well we are not dealing with a 3 porter, now that's where the fun starts.

I'm curious as to why there are relays in the wiring centre and actuators.
Now I'm wondering is it a 3 port valve that is installed.

I've come across plenty of Myson and Sunvic actuators with the aux stuck On or the motor getting weak and not fully rotating enough to reach the switch.

My zone valve of choice is Danfoss, I've seen them incorrectly wired resulting in being energised most of the day, every day, and still in good working order after over ten years like that.

K.Flyer · 19-01-2021 3:11pm

CrazyFather1 wrote: »

Thanks for help, got a chance this morning to take the motorised valve apart.

Pic attached

Thanks again

Can you take a picture showing the actual valve on the pipework, just curious.

John.G · 19-01-2021 3:22pm

K.Flyer wrote: »

It's as well we are not dealing with a 3 porter, now that's where the fun starts.

I'm curious as to why there are relays in the wiring centre and actuators.
Now I'm wondering is it a 3 port valve that is installed.

I've come across plenty of Myson and Sunvic actuators with the aux stuck On or the motor getting weak and not fully rotating enough to reach the switch.

My zone valve of choice is Danfoss, I've seen them incorrectly wired resulting in being energised most of the day, every day, and still in good working order after over ten years like that.

The mid position valve is truly a masterpiece as it uses DC pulses to stall the motor against spring pressure to keep it in mid position and also supplies a small de magnetizing AC voltage

CrazyFather1 · 19-01-2021 4:02pm

I think I have gone past my expertise and time to get someone in.
I tried to follow the wires back to the junction box but once back to the box it is a complete mess of wires and no idea which one is which. The image in original post is just a small section of it.
I took apart the motorised valve, from what I can see if I hold one connector to red and one to black which I expect is positive negative I get a reading
So I hold to negative and then to orange I get a reading. If I hold to grey/orange I get a reading as well. All while the boiler is happy to fire away.

The frost stat is interesting, what temp should that be set to? maybe that could be causing it but really I am in the dark now.

John.G · 19-01-2021 6:26pm

The frost stat is normally non settable and is ~ 4C or ~2C on newer boilers.

CrazyFather1 · 19-01-2021 11:43pm

John.G wrote: »

The frost stat is normally non settable and is ~ 4C or ~2C on newer boilers.

In the room they have a thermostat connected into the wiring. This has a standard wall thermostat connected to it. I guess this was been used as a frost stat?

John.G · 20-01-2021 8:38am

The frost stat is generally fitted fairly close to the boiler casing, may be at the rear of the boiler AFAIK.

CrazyFather1 · 20-01-2021 10:12am

John.G wrote: »

The frost stat is generally fitted fairly close to the boiler casing, may be at the rear of the boiler AFAIK.

I think I might have an odd setup, for some reason over the door I have a temp stat on the wall. A newer one to the one I have in the house to control the heating.

John.G · 20-01-2021 11:39am

Is this (boiler etc) located in a garage/outhouse? you might post a pic of this as well.

CrazyFather1 · 12-02-2021 11:19am

A few weeks later and no further on, got a plumber out. He said he would come back and now ignoring call. MY normal plumber is not available due to covid so pain in him.

I am wondering as this is more an electrical issue would a electrician be a better idea? Thanks

CrazyFather1 · 15-02-2021 12:59pm

Thanks for the help, just to update I got electrician in as plumber wouldn't reply. One of the automatic valves was gone and that is why it wasn't allowing the boiler to shut down.

Electrician said he would clean up with wires as well as it is a total mess

Boiler won't turn off

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