Central Heating Problem

  • Thread starter PottertonPrima30B
  • Start date


Hello all
first time on this site so here goes!

I have a central heating/boiler problem and the details are as follows:

The central heating system is not working.

potterton Pr1ma 30b boiler (at least 10 years old & thermocoupler replaced last year)
Boiler located in the garage.
Hot water tank located in house upstairs in the airing cupboard.
I presume there is a cold water tank in the loft? (pipes going up)
Pilot light is working ok and house thermostat is turned up.
Both timer & manual positions have been tried on timer panel in kitchen.
Hot water is all ok and water is nice and hot.
Can hear/feel the pump working (wsp-wilo salison Pump - Gold) in the airing cupboard as the water is being heated and the black box on top has a white knob switched to the middle position II (as always)
On the pipe work above this there is a grey box - acl Lifestyle - Mid Position Valve, and this appears to be working when the water is being heated.
When the water is being heated a couple of radiators upstairs have a very small area at the bottom where you can feel a slight amount of heat.
The timer is left on all year round however the house thermostat is always turned down.
Sorry but i'm not positive if the radiatorss have come on at all in Nov/Dec as i'm not always here, my feeling is that they probally have not ?

I will have to contact a gas engineer however would appreciate any informed ideas of a possible fault just to help me understand the problem so thank you for your help.
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28 Mar 2006
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Hedge End Hants
United Kingdom
depending on which ACL valve you have you can look at the paddle on its side to see where it thinks it should be directing the water.

the fixed one has the paddle, but if its fitted with the cylinder feed on the right its round the back!
the newer one is detachable by pressing the button on the opposite side to the paddle. you can unclip it to see the paddle.


Hello Kevindgas,

Thank you very much for your Professional Advice & let there be Heat !!

The gray acl box is placed lengthwise on top of a pipe with the bottom section 'cut out' on the left hand side (as you look at it) incorporating a black lever which was sticking out to the right. I applied some pressure to it and it pulled back towards the left and it pushed back into the grey acl body. It's a bit difficult to see the end due to it's position in the airing cupboard however using a mirror i can see there are no markings on the gray box casing. This leads me to believe this black lever is possibly some form of a pressure release valve ?? as it was quite firm to push back in and i can't see how it could have been moved otherwise ??
The heat started to come into the radiators within 30 seconds and they are still all piping hot an hour later. I can also hear the pump running nicely.
May I take this opportunity to Thank You so much for taking the time to help me with this problem, you obviously have a great knowledge of this subject. May I wish you and your family a Happy Christmas & Best Wishes for 2010

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