Potterton 50e

[dtww]

Hi all

Here, my first post...

My boiler Profile 50e stopped igniting just before Christmas and gas safe engineer replaced PCB and it started working again. (He also replaced the fan which looked end-of-life.) Soon after Christmas, I realised the boiler took a long time to ignite. At the timer start time, the fan will come on (sounds like the fan anyway), but nothing else happens. This stays so for about an hour (sometimes 30 mins, could be 90 mins). And then the flame comes on. Nothing 'wrong' with the flame. Radiators then get warmer and warmer. Good. However, it continues for about an hour, and then flame goes off. Radiators begin to cool down, down to solid cold. The boiler does not do anything at this stage, I can hear a low humming, I guess electricity. Fiddling with the thermostat at anytime does not do anything. So, no flame or anything from the boiler for another 30-60 minutes (or longer), and then flame comes on. And this repeats previous step, for about an hour. And the process repeats as before... gets hot, then boiler flame goes off and stays so for a long time, and then comes on. In about 6 hours, the flame comes on twice and during the radiators get hot, the rest of the 4 hours or so, nothing.

The engineer took some time to diagnose the previous problem which cost me a bit. I am more prepared to call him if I can provide some information for him to go straight to the problem and fix it. I don't even know during the non-flame time, whether there is actually hot water in the boiler. Does the boiler let the water cool down completely? Previously, the boiler reacts to thermostat and (as I understand it), when the water in the tank drops its temperature, the flame comes on to reheat it. But now, the flame does not come on "on demand", but when it comes on, it does so for 30-60 minutes at a time. When it comes on I don't want to fiddle the thermostat - it's very cold now, changing the thermostat might just reset the cycle and I have to wait longer!

The only clue I think there's *some* hot water in the boiler at the start of the cycle (timer on) is in the first 15 minutes or so, the radiators get a bit warmer. But very soon they cold down. And the long wait begin.

So, when the flame comes on, I guess it heats the water and also circulates to radiators... (you see my lack of technical). When flame goes off, it does not heat the water, NEITHER does it maintain water temperature (and not circulating hot water to radiator is almost beside the point, but relevant!)

I wonder whether the PCB is set to some kind of "timer" mode? i.e. (1) fan for a set time, then (2) flame on and circulate hot water for a set time, then (3) complete cool down for a set time; and then restart. I have checked for the rest button which is at the bottom, it stays depressed. I occasionally hear clicking sounds, irregular, but not during the "first stage".

Appreciate some suggestion of what ciould be the problems. Anyone had this problem before? Could it be that the pcb was not configured the right way?

Thanks for any help!

David

 

[Agile]

Was it the Happy Plumber?

I should think so if you were paying him by the hour to diagnose a simple fault.

These are pretty simple boilers and should not take more than 10-20 minutes to get an idea of the problem if they are reasonably accessible.

Tony

 

[ChrisR]

There's nothing "configurable" on these.
What you're describing is a standard fault though. A boiler bod shouldn't take long to find it unless he's new. A call to Potterton will tell him to measure one thing and look at another, which are pretty basic tests.
Sorry to be clandestine but the parts in question are safety controls so posts get deleted if we give details.

 

[dtww]

Thanks both. I thought of getting hold of Pot / BG but since you thought it's simple fix, hopefully previous enginner can sort it out. will ask him to get on the phone to P.

Incidentally, the timer came on yesterday 630pm but flame was on from about 755pm to 9pm. From then till timer off at 1130pm, only low humming. i.e. we had heating for an hour, for a timer of 5 hrs. The house is 11C. I assume no flame means no gas being used there, so electric heaters then, in the meantime.

David

 

[Agile]

I do not recommend any person who charges by the hour for diagnosis.

They have a vested interest in NOT diagnosing quickly ( or really at all ).

This is a very simple boiler but regardless does need a competent engineer.

I dont see your previous engineer as competent !

Tony