Potterton Performa 28i - Low System Pressure

[AdamH]

My Performa 28i was installed a couple of years ago and ran perfectly through its first Winter.

Towards the end of last Winter and since turning the heating back on a week ago I am getting a problem with Low System Pressure i.e. 0

This didn't occur during the summer when only hot water was required.

The problem is easily fixed by opening the valves at the bottom and raising the pressure to about 1.0 but this also sometimes has a knock-on effect of the pressure running at 3.5 when the radiators are on.

Any ideas?

 

[weareleeds]

Expansion vessel wants pumping up to about 1 bar air pressure if water comes out of schraeder valve when connecting pump then fit a remote vessel

 

[AdamH]

Thanks for this.

Am I safe to assume it's a professional job?

 

[weareleeds]

Check inst'n ins for blr but usually access to schraeder valve is from above @ rear of blr so no special skills reqd (just like pumping a car tyre up)

 

[Agile]

I supose I am safe to assume that you did not get the boiler serviced since it was installed?

Its unusual for the expansion vessel to lose charge within 4-5 years. Its more likely perhaps that its failed.

Possibly the installer was less than competent and removed some of the air charge when the boiler was fitted.

Tony

 

[aaroflewis]

I too have the same problem with my Potterton 28i. Pressure seems to be fine all the time the central heating is running. Seems to drop when the heating is turned off and I then run the hot tap and then run the cold. I presume that to repressure the expansion vessel I would need to remove the boiler from the wall. Jobs like a job for the pro's to me.

I have noticed that my installer has plumbed the filling loop into the CH outlet not the CH Inlet as is quiet clearly showing in the installation manual. What problems could this be causing.

 

[corgiman]

Its unusual for the expansion vessel to lose charge within 4-5 years. Its more likely perhaps that its failed.

Like TOm Jones says "its not unusal" these tony, they are just 105 instants re badged

under sized expansion vessels due to the heat store thingamajig

 

[Gasguru]

I find vessels typically only hold their charge for a couple of years - even the Vaillants are very poor these days. Must be due to poor quality vessels and being too small (some combi's now only 6 litre).

Afterall the old W+P vessels can last 25 years and hold pressure for several years.

 

[Simpson]

if you want to represurize your expansion tank the valve is easily accessable at the rear of the boiler look down from the top approx middle of the slot no mirrors or long hands required it is central and has a red cap. pump this valve up using a car tyre pump to 1 bar you wont get any further probs. by the way manual can be found at
http://www.partsarena.co.uk/baxi/System/DATA/Dx/DS1/installation/2201/I04-2201/I04-2201.htm#zFig6

but it does not give the location of the valve its one of the best kept trade secrets!!!

 

[Agile]

Its a bigger secret where the air cap is on the ideal sprint!

The last remaining working model ( but one ) that I know has a pin holed EXV! But I made a rad into a temp EXV as I like the owners sister but I gather that she has been squeezed out to make way for the owners boyfriend now.

Tony