Suprima 30 running by itself

[blushy]

Just come home from work to find my house really really hot and found the boiler to be running when the heating controls (Potterton EP2) were on standby and the stat for the room temp was not lit up as in heating and water off.

The heating timer went off at 8am like normal and the heating and hot water are off all day and come on at 3pm but I came home at 2pm to the hot house!

I turned off the common mains electricity supply to the boiler as the heat was just too much.

So now I don't know whether to suspect the timer, boiler, stat or 3 way valve! Any ideas?

 

[ollski]

timer - likely, stat - no, boiler - unlikely, 3 port valve - possible, 2 x 2 port valves - very likely. 100 minutes with a multimeter will give you the solution.

 

[blushy]

From the FAQ is my best bet is to check the voltage on the Orange wire in the airing cupboard where the valve and pump meet? 240v=sticking valve 50-150v something else.

No 2x2 port valve, just a 3 port.

 

[ollski]

If it's an older acl lifestyle actuator I've had a lot of these fail to turn off as the heat causes the big solder blobs to expand on the actuator pcb and grey and orange touch causing demand. The newer ones are redesigned.

 

[geoff@cetltd]

Just come home from work to find my house really really hot and found the boiler to be running when the heating controls (Potterton EP2) were on standby and the stat for the room temp was not lit up as in heating and water off.

The heating timer went off at 8am like normal and the heating and hot water are off all day and come on at 3pm but I came home at 2pm to the hot house!

I turned off the common mains electricity supply to the boiler as the heat was just too much.

So now I don't know whether to suspect the timer, boiler, stat or 3 way valve! Any ideas?

Is there a perm. live feed to the switched live?
have the relay contacts in the timer / stat welded themselves in the normally open position?

 

[blushy]

The boiler hasn't malfunctioned since it did it initially but when the boiler is operating now it seems to make a high pitched noise similar to a kettle. Seems to do it more on the CH than the HW, any ideas please??