Thorn Emi Olympic 38 50b - programmer on, CH but no HW!

[Damianparker]

Hi,

Have the above boiler with a hw cylinder in the airing cupboard upstairs, along with programmer. This week, I noticed the boiler was continually running when the programmer should have been off.

On checking the programmer was indeed off, however the CH was red hot! On further inspection, once the rest of the hw was run through the taps, no more has been produced, even once the programmer is meant to be on. Also the room thermostat in the lounge, although clicking when turned down or up to indicate the pump to start stop, this has no influence over the pump. It purely stays on!

I have resorted to turning the rads off in some rooms, most are original without their own settings when heat is needed, and using the mains power switch to shut off the programmer and pump. This then shuts the burner off in the boiler, just the pilot on. The boiler is very warm, but no water is being distributed into the hw cylinder and all pipes to and from the cylinder are cold.

Could this all be caused by a faulty valve? If so who do I need to replace the valve for me, I'm assuming it's the electrical divert valve for moving water though to either both hw and ch or just hw?

Any help appreciated ASAP - we need showers!

Thanks

Dp

 

[namsag]

You have a few faults
microswitch is stuck in motorised valve keeping boiler and pump on.
Do you have 2 two port motorised valves or 1 3 port

 

[Damianparker]

I believe it's a 3 port valve - ie. it's got 3 tubes joining together at the box. The box has a cable running to it from the programmer, and the model number is va073a1039' cannot see any branding but all other components are Honeywell.

 

[namsag]

Sounds like Valve has jammed in the CH position keeping the microswitch activated.
It might be the shaft on valve seized which would mean a whole valve would be req or it might just be a faulty head,

 

[Damianparker]

Thanks, will this just require a corgi reg plumber to fix? What about the issue of the programmer being over-ridden and running whether the controller says it should be off or not?? Obviously I guess the room thermostat is being overridden by the motorised valve not closing when the temperature is reached, hence why it just keeps getting hotter and hotter?

I have tried moving the valve lever underneath the motor box to manual,but this has no effect.

Any further help appreciated....

Dp

 

[Damianparker]

Bump