Potterton Problems

[fotoman]

I have a Potterton Performa 28i that keeps losing pressure and the hot water takes ages to come through. The flow rate is not particularly good either. (It's coming up for 3 years old and had a descale last summer)

Central heating rads are working fine, nice and hot, but the hot water is not hot. The hot water thermostat is up as far as it will go.

The unit is in my loft, so getting up and down to turn the pressure valve is a pain. Once I've done that, the hot water is much better but not perfect.

I've checked for leaks in all of the rads but cannot find any.

Any ideas guys?

 

[corgiman]

probably the expansion vessel

 

[tukky142]

I have the same boiler and have had a new expansion vessel. I would recommend de-pressurising the boiler and checking the expansion vessel with a car foot pump with gauge - it should be 0.5 bar.

Note I had the new vessel a year ago and I have had to re-pressurise it again this year - I think they are not very robust.

My hot water temperature has never been brilliant either.

 

[Lemoncurd]

Ours had been losing pressure (didn't have a problem with the hot water temp though) and then it started leaking and the pressure suddenly went right up and activated the pressure release valve.
We've also been told that a new expansion vessel is needed as it deflated quickly after being pumped up. Don't have a proper quote yet but we've been told that it will cost around £500- 600 to replace, does this sound right?

 

[corgiman]

you need to take the boiler down (if an instant model) off the wall to replace the expansion vesssel, that can be a git, and the expansion vessel is about 150 i think

so allow two to three hours work plus inhibiter etc

 

[tukky142]

our expansion vessel was changed without removing the boiler from the wall - 500 to 600 is far too much - someone is ripping you off - you should budget for 100 plus the vessel

 

[corgiman]

i would say 100 labour is a bit low

maybe 200

 

[chrishutt]

Just fit a new 8 litre expansion vessel (£20?) outside of the boiler, connected to the return pipework. Easy and cheap.

 

[corgiman]

you cannot if its the instant version chris as those divs at potty utilize some of it for storing hot water

sorry

 

[chrishutt]

Ah, didn't know that. Not many Pottys round my way. But couldn't you leave the old expansion vessel to do this hot store stuff and fit a new EV to do the EV stuff?

 

[corgiman]

same boiler as the baxi 105e instant (a piece of **** lol)

what a great design eh? a 8 litre expansion vessel is usually too small anyway then they go and nick some of it for a crappy heat store. And another great idea lets put something thats going to need changing lots at the back of the boiler

 

[fotoman]

Thanks for guys. At least I've some idea of what it might be.

My regular plumber is still taking the course on Potterton servicing but has recommended a colleague of his who has given me a price of around 200 pounds. But he's mentioning something about the pressure release valve and the need for another descale.

I'll suggest looking at the expansion vessel.

Thanks again.

 

[corgiman]

not a bad idea to change the PRV just in case it will not seal up after it has been blowing

as for descaling, i cannot see why even if all the inhibiter has been removed by all the refilling that you have done, I dont think scale would have built up so quickly so adding some fernox (or summink else) would be fine

200 is a great price to change the expansion vessel on these, snap his arm off

 

[Baxi-Remeha]

the boiler might not need to come off the wall, it is possible to get it out of the top, if you have enough room, just disconect the flue, and remove the gas valve for access, and if you want it realy easy remove the pump, its much quicker doing it this way, average takes about 1 1/2 hour if everything goes right.....

also if you boilers under 7 years old, call heateam i belive the cost is about 189 for an appliance under 5 years, and 259 for one over 5 years, and that is a fix fee, includes all call out, parts and labour (prices may not be exact, but not far off)...

 

[corgiman]

youd be very very lucky to have .75 mt above a boiler to do that, I have changed loads of these git bloody things and never once had enough room to do that jason.

but your right if you can then it is easier