potterton puma 80e



can anyone help, I have a potterton puma 80e, the CH is working of sorts, but I have no water coming out of the hot taps, I get a little trickle then the boiler makes a lot of noise, I have checked the inlet filter in the isolation valve going into the boiler and the scalemaster but they are all clear.
could'nt have happened at a worst time as I have lots of relations staying.
any help would be appreciated
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Pumas had a peculiar wax capsule device in the diverter valve assembly. You will need a pro to sort this one out. Like most Potterton boilers, they had controls that were too clever by half.
The wax capsule flow restrictor reduces the flow to about a third until it becomes hot.

I think the capsule can be removed from within the unit.

Myself I have never attended a failed one and you have not measured the actual flow that you are achieving. I would expect there is another cause and I think there is a flow restrictor near the inlet filter and suggest you check that and probably remove the rubber ring in it.

As there is virtually no water coming out of the tap, is it a real possibility that the heat exchanger is blocked or is that an unusual occurence.
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You dont bother to say where you are located so I cannot judge the hardness of the water in your area.

However, unless you have dripping hot water taps then its very unlikely. I have never encountered a Puma with a blocked DHW coil.

I am in Bognor Regis, the water is fairly hard, kitchen tap has been dripping for the last couple of weeks, but fairly certain it is on the cold side, it is of the ceramic disc type.
I am happy that you don't think it's the heat ex' as I have been told they are a bit of a pain to change on this boiler type.
Can you test to see which tap is dripping?

Although if it was the hot the boiler's diverter valve should hold the heating off.

It is the cold main to the kitchen sink that is dripping.
heat exchanger is blocked solid, is it worth trying to clear it or bite the bullet and replace?
You can still get the main heat ex but to be honest i wouldn't spend any more on it as it will cost hundreds.

New boiler time
thanks for the advice, I think your right,new boiler time it is.
I would clean it using HCl in my case but thats messy and potentially dangerous.

Of course a DIYer should not be removing the main heat exchanger!

thanks for the advice Tony, and your right I know my limits and this is one for the professionals.I just have a curious nature and like to understand what makes these things tick.
Afterthought! Have you measured the resistances of the two sensors?

Are you sure there is no leakage from the hot water output circuit?

Its possible for a diyer to concoct a pump and circulation arrangement to circulate chemicals throught the DHW path.

Its not essential to use HCl as sulphonic acid is quite good at 80 degrees.

But most chemicals are dangerous and particularly when hot and to the eyes.

i disconnected the hws after the inlet valve in the boiler and disconnected the the hws at the diverter valve, so with no other control valves on the circuit and just the inlet and outlet to the hex open i blew down the pipework and could not get even a puff of air through the pipe, so I can only think that the hex is blocked solid.
have a good new year.

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