Boiler driving me nuts....

[Atlas]

Hi all,
we have a Potterton Performa 24 that was here when we moved it.

Recently its started playing up. When you run the hot tape the boiler burner light comes on after a while, stays on for about 10-20 seconds then goes out for 10-20 seconds, then comes back on, this continues. This means you get hot water for a few seconds, then cold, then hot etc.

Once in a while it will work fine, havent managed to figure out why.

Had a plumber out today and he replaced one of the sensors and cleaned a heat exchanger and spent ages on the phone to potterton, finally it started working.... for a few hours, now the problem is back.

Anyone know what could be causing this?

 

[dcawkwell]

Sounds like the whole heating system needs flushing and the plate heat exchanger cleaning out as it keep blocking up.

 

[Atlas]

Yeah, it looks like we might be heading down the route of a new boiler.

He did suggest a powerflush, my concern with that is that is an old house/system and dont really want to risk pipes leaking under the floors etc.

 

[dcawkwell]

Yeah, it looks like we might be heading down the route of a new boiler.

He did suggest a powerflush, my concern with that is that is an old house/system and dont really want to risk pipes leaking under the floors etc.

I would suggest draining, refilling, running the central heating, draining
refilling a number of times first that would hopefully get most of the system clean and see how you go from there.

 

[bengasman]

Yeah, it looks like we might be heading down the route of a new boiler.

New boiler will do little to solve this problem, you'll have the same symptoms coming sooner rathar than later.

He did suggest a powerflush, my concern with that is that is an old house/system and dont really want to risk pipes leaking under the floors etc.

A powerflush doesn't make pipes leak on a sealed system. It may expose existing leaks though.

 

[Agile]

So what does the plumber have to say?

What was the colour of the water when he opened up the system to clean the secondary heat exchanger?

 

[Atlas]

Plumber is coming back today.

He suggested an alternative to a powerflush would be to put something in the system (cant remember what he called it) and then run the heating for a few hours for three or four days, then he'd come back and drain the system, and replace it with an inhibitor....

 

[Atlas]

Well he changed another sensor today, but it had no affect.

Tomorrow he's going to try changing the gas valve (i think), as it was spluttering while the flame was on. After that hes out of ideas and reccomends a new boiler.

 

[bengasman]

After that hes out of ideas and reccomends a new boiler.

I would recommend a new plumber. Or even better, a real heating engineer.

 

[crashndie]

even if you fit a new boiler, your system will need power flushing as per the benchmark. a cleaner will not really flush the sludge out of the system, it will brake it up and just be moved else were. get it flushed proper, if it leaks it leaks. ive done 000's of flushs and ive only ever had 3 minor leaks.

as for the boiler i dont think the gas valve is the problem, did he check what voltage was going to the valve ? dose it work ok on central heating ? is the boiler making any kettling noise while the hot water is running?

 

[Baxmax]

Check out the a.p.s and the a.p.s tubes and a.p.s venturi...for blockage or meltage [is meltage a real word ?]