problems with puma 80e

[felts]

i have a potterton puma 80e.
when i turn on the hot water, the boiler keeps turning its self off and on.the water remains hot.this has been happening for a while.
yesterday i turned the heating on for the first time for months.it worked fine.
today when i ran a bath the boiler made some loud dodgy noises.
later i turn on the hot water to do some washing up.
again the boiler made some dodgy noises, but then after i'd turned the tap off the boiler kept going (the heating is not on) and the radiators started to warm up.the hot water demand light stayed on.
i also notice there's a little amount of water coming from the automatic air vent.

help

 

[kevplumb]

View media item 15622
this bit is sticking

ask me in a nice way and i will post the GA for you

 

[felts]

hi kevplumb

whats a GA

thanks

 

[kevplumb]

general arrangment View media item 14647
never had to work to drawings i take it

dhw flow switch is what you want

click the pic to enlarge

if you put an e mail addy in your profile i will send you "the book"

 

[felts]

hi kevplumb
i have added my email address.

thanks

 

[Agile]

You seem to have two problems, the DHW flow switch staying on after a demand and the hot water going hot/cold.

The second can be caused by a too low water flow rate. The boiler is designed to heat about 8-9 litres per minute. If the flow rate drops below about 4-5 li/min then it can cause the burner to go on/off as the minimum power is too much for heating that flow rate.

It can also be caused by a mis setting of the gas valve but thats a job for a gas registered person.

Tony

 

[kevplumb]

hi kevplumb
i have added my email address.

thanks

sent

 

[felts]

hi kevplumb

thanks for your help, i left the wrong email address.
i've now updated it.

thanks

 

[kevplumb]

wondered why it bounced

sent again

 

[felts]

what about the small amount of water coming from the automatic air vent.
is this to do with the water flow switch or a seperate problem ?

 

[bengasman]

Your system is full of crap, it needs cleaning. Could well be that this has wrecked your diverter as well, they are not very good on this model

 

[Agile]

The auto air vent is a third problem.

Best to replace it. If left they drip on the £120 gas valve and spoil that too!

Tony