Potterton Profile 80e- Bled rad do I need to refill?

[BenHutton]

I inherited the above boiler on our new house. All works fine despite looking fairly old. One of the rads wasn't warming up so I bled it but after the hiss of air no water followed. I had a modern boiler in my old house and after you bled the rads you had to refill the system under the boiler. I've read all the instructions but there's nothing telling me how I refill the system. There's also no obvious pressure gauge. There are a couple of Honeywell Motorised Zone Valves located under the boiler. These are all set to auto. Is it possible these control the system pressure?

Sorry if I've completely missed something- not really my forte.

Cheers!

 

[lightning]

Heating is fed by a small f/e tank in loft, radiator valve pin might be stuck that's why rad not warming up.

Paul

 

[JohnD]

this boiler very likely has a feed and expansion tank in the loft. It will probably be about 60cmx30cmx30cm with a ballcock inside like an old WC cistern. There will be a 22mm pipe above it, bent into an inverted "U" shape. It is probably black plastic and should have a tight-fitting plastic cover, and an insulating jacket. See if there is mud, insulation or drowned wildlife in it.

In which case, what you are describing suggests that water is not flowing down the pipe from this tank to refill the system. Try to find it and have a look. If you are relatively lucky, the ballcock is old and seized, and can be freed up or replaced. If you are unlucky the tank is full but there is a blockage in the feed pipe. This is not uncommon with an old system like yours.

Do you own or rent?



p.s.
your radiator has a valve at each end. Only if they were both closed would it fail to fill.

 

[BenHutton]

After I bled it some more having given it 10 mins water suddenly appeared so presume there was just some delay in the system filling itself. I have seen that tank in the loft and had wondered what it was!

Cheers for your help.

 

[JohnD]

it is an old system, and there is doubtless old sludge and sediment in the pipes. The boiler is iron so there will be black iron oxide and other detritus. This may have caused the temporary blockage.

It would be a very good idea to give it a clean before you get your first blockage. Once you get a settled blockage, you will not be able to clean it because chemicals will not circulate through the pipes.

You will need to start by baling out the F&E tank top remove all the mud and sludge you find, then drain a couple of buckets of water out of the drain cock, then add a chemical cleaner such as X400 before refilling and run it for a few weeks to loosen the sludge and sediment.