Potterton Profile takes forever to heat water

[aggi]

Since moving in to our home last year we have had very little luck with our central heating system. On calling out a local engineer we were told that all was well and we simply had to balance the rads!
I called them out again but still had no joy and so before I hand out any more money I thought I'd try my chances on the site and see if anyone can help (please!)

The boiler is a Potterton Profile (cant remember the model but can have a look if needed). It is a gravity system with circulation pump and 3 port valve. From what the engineer said all is working fine but that doesn't explain why it takes 8 hours to heat the water to have a bath. Currently we have the HW on constant and CH twice for about 6 hours at a time (and that's to heat 2 radiators as that's all we can get working). One of the rads that work is hot at the top but warm to the bottom and both rads have hot flow but warm return pipes.

Would a build up of sludge be the cause of our problems?

Any help or advice will be much apreciated.

Many Thanks

Aggi

 

[StarTech70]

If you had a problem with circulation the Profile has an overheat stat in-built which would trip the boiler making it inoperative. Try turning the rads that work off to get the CH circulating to the other rads and try adjusting the pump speed upto 3 if its a Grundfos.

Dependant on your area you could have a cylinder full of lime-scale.

 

[seco services]

quite poss a sludge issue but can also be many other factors aswell.

has the return from the coil on the cylinder fitted with a gate valve at all ?
whats the condition of the water in the f/e tank in the loft ?
are the rads fitted with trv's ?
whats the boiler stat on ?

did the engineer not look at anything apart from tell you to balance the system ?

 

[aggi]

Thanks for the speedy response.

To my knowledge the boiler has never tripped out as I have never had to reset it (unless they reset themselves once cooled).

Will check to see if there is a valve on the cylinder return when I get home tonight.

The water in the header tank is pretty clear with a few deposits (scale maybe) at the bottom.

No trv's on the rads.

The boiler is on about 3 or 4, we originally had it up higher but the engineer told us to turn it down.
Unfortunately both times the engineer came out I wasn't at home but on the second occasion a couple of people came around and the woman with them told my wife that the rad in the hall was the important one as though if we get that working all will be well.

Thanks again

Aggi

 

[StarTech70]

The overheat stat doesn' t reset itself, you have to pop the switch back in yourself. The grey facia underneath the boiler has a hole in it, stick your finger in there and hey presto, there' s your OH stat.

You sure its gravity when you have a 3port valve also ??

 

[aggi]

I say gravity but maybe thats not correct. It has a header tank above the boiler with a ball valve. So does that make it an open system but not gravity?

Cheers

 

[StarTech70]

does the cylinder have a thermostat attached to it, 2/3 of the way down ??

 

[seco services]

I say gravity but maybe thats not correct. It has a header tank above the boiler with a ball valve. So does that make it an open system but not gravity?

Cheers

its a fully pumped y plan system

 

[aggi]

Hi again..

The return from the cylinder does have a gate valve which is fully open (at least it turns to close but not the other way).

If the cylinder was full of limescale how would I treat it?

The cylinder does have a thermostat attached to it and it seems to work. Last night, after it had been heating the hot water for 6 hours after a bath, I tried turning it down and the pump went off after I got to about 2 and then came on again when I turned it up.

 

[seco services]

from closed how many turns does it do to its fully open ?

 

[aggi]

Will have a look later and let you know..

Thanks to you both for your help so far

 

[StarTech70]

set the cylinder stat to 50-60 Deg. Cent or 120 Farenheit which' ll give you close 50 Deg. , adjust accordingly to suit your dhw needs.

 

[aggi]

The gate valve takes 2.75 turns to go from open to closed.

The cylinder stat only has numbers between 1 & 6 and we generally keep it on the highest.

Currently we have hot water on constant and CH between 7am-1pm and 5pm-11pm. If we have a bath at 10am the water wont be hot enough at 7pm to have another (kids bath time). We are only heating 2 rads out of a possible 10.

Thanks

Aggi

 

[aggi]

Hi all and Merry Christmas.

Don't know if you are still following this thread but if you are would like some advice on the latest.

I am now thinking of swapping out the hot water cylinder so that we can have a working immersion to heat the hot water.

We have supplementary heating for the house so although it's not ideal we can live with the heating as is but the HW situation is a nightmare.

Have done this before on a boat we once had so not too put off by it but wondered if you thought it was a stupid idea.

Cheers

Aggi

 

[Garfeild]

If you select hot water only,what does the boiler do? does it cycle on/off or does it stay alight for some while.?