Potterton Prima - luke warm hot water and tripping out

[wills100]

After getting some great advice on here a year ago which fixed the problem, I thought i'd try again with my latest heating problem...

Over the last few weeks the hot water to the taps has been getting more and more lukewarm. The HW tank stat is fairly new and both motorised valves seem to be working ok. Possibly related is that if I turn up the dial on the boiler itself to anything above about 2.5 the boiler trips out and has to be reset several times a day. Today I set it to 3 and its needed resetting about 3 times. Until recently the dial was always at about 4 and the water temp was fine and no tripping.

A year ago the boiler had a new flue kit and PCB, it's been fine since then, until now.

All ideas and advice gratefully received!

Thanks,

Will.

 

[bengasman]

Open vent, so first suspect is corrosion

 

[wills100]

Sorry corrosion where and causing what? Could you give me some more detail please.

Thanks.

 

[bengasman]

Search the forum, must be 1000+ posts on the subject

 

[Ray84]

i think you'd need to aquire the services of an engineer.
Your boilers obviously cutting out due to overheating and theres far too many possible causes but shouldnt take an engineer on site too long to diagnose.
Could be a component failure i.e. pump or a blocked up heat exchanger etc
but cause more than likely to come down to corrosion/sludged up system.
if you can live with it justnow why not search numerious posts on putting a chemical cleanser in to see if it improves the situation?

Ray

 

[Agile]

Most likely to be a faulty pump or a sludged up system.

As a first step put heating on for 10 min with room stat at 30 C.

Then feel the two pipes out of the boiler and see how different the temperatures are. Should be about 10° C difference!

See what speed setting the pump is on and tell us.

Tony

 

[scoobydo123]

OP any news.

Follow what Agile has said, I would also look to confirm that the pump over run is working after following his advice. Set boiler to max and also have the roomstat and cylinder (if fitted) stat set higher than normal. Let flow and returns get up to operating temp then turn cylinder stat/roomstat down individually. If you have a suspect pump overun or not working whatsoever then this will cause the trip.