Honeywell 2 port valve faulty microswitch ?

[robbie77]

Hi

I have an S Plan plus pumped CH system with motorised valve for upstairs and downstairs heating.
Both upstairs and downstairs have a T6360B1036 that calls the boiler. The downstairs heating thermostat fails to call for heating, it makes an audible click but the boiler does not fire.
I was not getting any voltage reading on pin 10 on the wiring for the boiler which I think is switched live for the boiler.
When I move the upstairs ther,mostat all works as expected.
So this sounds like a faulty thermostat? Is there much to go wrong or anything else to try?

Thanks

 

[CBW]

You don’t check at the boiler. You need to check the switched live in the thermostat, so between neutral (2) and live out (3). If you’re getting 230vac then the thermostat is fine. So it’s probably going to be the motorised valve, as this then sends the live to the boiler. Are you saying if you turn on upstairs, then downstairs heats up?

 

[robbie77]

You don’t check at the boiler. You need to check the switched live in the thermostat, so between neutral (2) and live out (3). If you’re getting 230vac then the thermostat is fine. So it’s probably going to be the motorised valve, as this then sends the live to the boiler. Are you saying if you turn on upstairs, then downstairs heats up?

OK Thanks.
No Upstairs heats upstairs. Just downstairs not working. Will do as you suggest and report back

 

[robbie77]

You don’t check at the boiler. You need to check the switched live in the thermostat, so between neutral (2) and live out (3). If you’re getting 230vac then the thermostat is fine. So it’s probably going to be the motorised valve, as this then sends the live to the boiler. Are you saying if you turn on upstairs, then downstairs heats up?

I have checked the voltage between pins 2 and 3 and all is well at 240v.
I can access the motorised valve and wiring i am not sure the orange wire is live when thermosat is on ? Is that how I would check?

 

[Elkato531]

You could try switching the thermostats over and if the upstairs/downstairs working/not working is reversed, you will have your answer.

 

[robbie77]

You could try switching the thermostats over and if the upstairs/downstairs working/not working is reversed, you will have your answer.

Yeah might have to do this. The upstairs thermostat when turned makes the orange wire live on both port valves but the downstairs does not?

 

[CBW]

I’d say the motor isn’t moving, or the microswitch isn’t being made. Move the lever on the valve to manual with the demand in place and see if it then fires up/makes the orange wire live.

 

[robbie77]

I’d say the motor isn’t moving, or the microswitch isn’t being made. Move the lever on the valve to manual with the demand in place and see if it then fires up/makes the orange wire live.

I Have tested the wiring from the Thermostat through the wiring centre to the valve wiring where the light brown wire becomes live when thermostat is turned but the orange wire does not go live? I have placed the valve manually on open.
I have an old valve somewhere (this one is just over a year old maybe) can I swap some bits from it do you think?

 

[Gasguru]

If the motor is receiving 240v (on the brown and blue) it should rotate the spindle about 15 degrees and operate the microswitch. Sounds like the motors stuffed...they either properly die or partially and don't have sufficient torque.
The Drayton bagged motors are the only genuine motors out there...pretty much all the others are knock-offs and often only last 18 months.

 

[robbie77]

If the motor is receiving 240v (on the brown and blue) it should rotate the spindle about 15 degrees and operate the microswitch. Sounds like the motors stuffed...they either properly die or partially and don't have sufficient torque.
The Drayton bagged motors are the only genuine motors out there...pretty much all the others are knock-offs and often only last 18 months.

It's a Honeywell valve I bought from Amazon. I am not getting 240v to blue though?

 

[Gasguru]

Forget the lever it's only for draining/filling and does not operate the switch.
So you're getting 240V from the brown to earth at the actuator then? If so you've got a neutral fault so check the blue.

 

[robbie77]

Forget the lever it's only for draining/filling and does not operate the switch.
So you're getting 240V from the brown to earth at the actuator then? If so you've got a neutral fault so check the blue.

Yeah getting 240 v from brown to earth. The blue from the 2 port valve goes to a junction box that then goes back to the wiring centre. I get 240v from the blue from the valve but when I connect to the junction box its no longer getting 240v??

 

[CBW]

Forget the lever it's only for draining/filling and does not operate the switch.

If this is the case, why does mine operate the boiler if I move the lever to manual?

 

[robbie77]

Yeah getting 240 v from brown to earth. The blue from the 2 port valve goes to a junction box that then goes back to the wiring centre. I get 240v from the blue from the valve but when I connect to the junction box its no longer getting 240v??

The other valve is the same the blue wire when connected to the junction box loses 240v not sure why but red herring i think.
So the only difference between the two valves is the orange wire on the downstairs is not going live.
this is controlled by microswitch?
Thanks

 

[robbie77]

If this is the case, why does mine operate the boiler if I move the lever to manual?

Is your valve a honeywell 2 port also? I have an old one here in the kitchen and it looks like if you manually move the lever to the manual/open position then the lever almost hits the mircoswitch. The one I have has been taken apart a bit so doesn't quite make it but it may have once!?
So this is what is wrong with mine? The micro switch is not getting pressed for some reason, looks like some cavity insulation polysterene balls around this area I wonder if some have got in and blocked it.