Potterton Puma 80e fixed - thanks!

[GeeTee]

Just wanted to say thanks for all the informative posts on here.

Recently started having a problem with my Potty combi, where the CH would not stay on for more than 30 seconds, switch off for about the same then cut back in.... on off on off on off.... so the rads were only getting lukewarm at best.

A bit of poking about on here and gathered it was the diverter valve. Just changed the wax head this afternoon and now everything is toasty

Easy job too!

Cheers guys.

Graham

 

[Agile]

I hope that it was not just a leaking hot tap!

 

[GeeTee]

no I checked that.

we only have 3 hot taps and they're all fine.

Although I do think there is another problem due to uninhibited water being in the system - the div valve push rod thing was coated in a kind of black limescale. And the water I drained out of the boiler was black with bits in it.

Thinking of lobbing some X400 in it for a couple of weeks then get it properly inhibited once it's been drained and flushed a few times.

Don't think it needs a powerflush.... all the rads get hot all over nice and quick.... I'm afraid a powerflush would disturb sediment that;s not actually doing any harm at the mo.

Oh... and why would a dripping tap cause the wax capsule head to fail?

Cheers
Graham

 

[Agile]

It does not cause it to fail ( permanently ).

Because of the way the diverter works, if there is a tap dripping the valve stays in the DHW mode. The owner then thinks the boilers gone wrong.

Tony

 

[GeeTee]

Ahh... OK makes sense.

I'm absolutely sure none of the taps drip, and I presume that if they did then swapping the wax head wouldn't have fixed the problem

X400 going in tonight. Probably leave it til the weekend (or maybe the one after depending how heavy this weekend turns out ) then fill and drain it a few times. Then got some X100 for the final fill.

Cheers
Graham

 

[Agile]

If you put X400 in you have to leave it for at least FOUR weeks and then fully drain out the system.

NOT four days!!!

Replacing the wax stat can fix it because a weak old wax stat is more sensitive to dripping taps.

Tony

 

[GeeTee]

Oh OK. The bottle says minimum 2 hours with with all rad valves fully open but can be left in for up to 4 weeks for badly sludged systems.

I'll leave it for a few weeks then, give it a chance to do it's worst.

Thanks for the advice.

Graham