Potterton 40 boiler trips out with timer

[j.jackson76]

I have a potterton 40 boiler, for my sins. The system is fine when it is running on constant setting. When I put the system on timed it comes on ok then when it shuts off and then comes back on, it trips the fuse and I have to replace it. Does anyone know what the problem is? and how much money it will cost to fix this. I have had dozens of so called experts round, who have changed the PCB, cylinder thermostat, control panel under the boiler and the pump. The company now are telling me that this is a problem with my electrics and that they can't do anything else. I'm no electrician but it seems like it is has something to do with the timer to me? Can anyone give my some advice please?

 

[PEDANTICVINDICTIVEMAN]

To stop the boiler and timer tripping take away their drugs.

 

[joe-90]

If you've changed all those things I can't understand why you didn't try a new timer? If you went to B&Q and got one and it wasn't the timer - you could have taken it back.


joe

 

[chrishutt]

Sounds like a problem with the mid position valve, assuming you have one (???). The microswitch and associated components might be causing a short. What make and type of motorised valve do you have?

 

[meldrew's_mate]

Sounds like a problem with the mid position valve, assuming you have one (???). The microswitch and associated components might be causing a short.

I too would opt for this, but even on constant heating the valve would modulate as normal, leading to similar.

.....UNLESS.... you have a leak on the valve shaft (this is a statement of possible fact, NOT an instruction) which evaporates when the valve is hot, when timed it leaks and soaks that card bit in the valve, which.....Chrishutt, your right.

Look for signs of leakage around your (possible) valve, change it as necessary. Hope it's not upside down!

I once advised a woman to turn her immersion heater onto timed (all electric house) to save money, I even set up the timer for her. Got a call next day to say no hot water, hot-footed it down there to find 15A rewireable fuse blown. Replaced fuse, fuse blew 2 mins later. Guess who got the blame for "breaking the heater"? I didn't hear any more, she probably wrote to Trading Stds & Watchdog etc., but suspect the permanantly on imm htr kept the leakage current from the corroded element low enough to prevent fuse blowing. Allowing it to cool sent it over the edge. A lesson learnt