Boiler won't turn off

CrazyFather1

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

Sorry anyone give me an idea/ Thanks

John.G

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

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

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

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

Pic attached

Thanks again

John.G

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

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

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

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

Froststat overriding everything?

meercat

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

John.G

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

Have you changed battery in thermostat

CrazyFather1

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

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

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

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

K.Flyer

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

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

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

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

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

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

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

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

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

K.Flyer

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

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

K.Flyer

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

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.