potterton 24 hot water problems....

[pil]

Hoping this can be a simple yes answer!!
I have a problem with the hot water supply from the potterton 24 (not the HE model)
Heating works perfectly, no problems there but when hot water side is operated a number of things occur
1. No hot water!
2. boiler operates briefly
3. gurggling noises
4. pressure gauge increases and reads erraticly
5. central heating flow pipe gets hot up to a meter or so from boiler
6. boiler shuts down

As its attempting to issue heated water along the central heating line, but without the pump operating (thus giving heat along the short section of flow pipe) and the noises/ pressure increase/ boiler shut down, would this point to the 3 way valve not switching/ sticking? If so, is this part stripable or replacement only?

 

[picasso]

blocked plate heat exchanger would be first on the check list.

 

[pil]

blocked plate heat exchanger would be first on the check list.

Far be it for me to argue here, and thanks for quick reply, by why would heated water be sent along heating flow line when its not on? My thinking was that the (over) heated water thats been incorrectly distributed down the heating flow and unable to be dispersed as the pump has not been energised as its not been required has caused the combination of no heat from hot water line and the gurgling from boiled water with nowhere to go, plus the shutting down of the boiler because of the excess heat......like i said, just my way of thinking. Or am i reading too much into it...

 

[Beerlover]

You've asked for advice and Picasso has given you exactly that

If the plate heat exchanger is blocked, as I guarantee it will be, the heat has to go somewhere.

Check the plate heat exchanger and remember to thank Picasso

 

[45yearsagasman]

As said above, the plate exch requires attention and I bet your diverter valve needs some work as well.

 

[pil]

You've asked for advice and Picasso has given you exactly that

If the plate heat exchanger is blocked, as I guarantee it will be, the heat has to go somewhere.

Check the plate heat exchanger and remember to thank Picasso

Beerlover, i was looking more for an explanation than an to be patronized! I am grateful to Picasso and was hoping that he could give the reason for his input rather than to disagree with what he suggested. I am also aware of the THANKS button, but thank you for kindly pointing it out anyway Also, thank you for explaining the reason that the heat had gone down the central heating route as it had nowhere else to escape.......

 

[Agile]

When the plate becomes blocked the pressure across it rises perhaps fivefold and that accentuates any leakage in the diverter valve.

When the plate has been cleaned the leakage in the diverter can be assessed and a decision made as to whether replacing the diverter valve is necessary.

The same dirt which blocks the plate also sticks the diverter manifold section.

Tony

 

[pil]

Absolutely perfect, can see how and why that would happen now. Was kind of on the right line, had just skipped the reason that any leakage would occur in the diverter valve! Will descale plate and see what happens from there. Many thanks. Will advise findings in the week.

 

[Agile]

Amazing how a simple and clear explanation helps!

But I should really be out mending boilers on a chargeable basis and not spending time giving free DIY advice!

Tony Glazier

 

[pil]

Glad you do though! Im a HGV mechanic and always try to advise customers on things they can try and do to cure a fault before bringing it in. Brings a lot of satisfaction knowing youve helped......

 

[pil]

Just a quick update, have changed the plate heat exchanger and all is well, so many thanks to all that took the time to help. Although i have only operated the hot water for about 5 mins, during that time no heat has fed through to the central heating circuit so maybe i have got away with the diverter valve......for now! Is flushing the system with an additive and the adding of an inhibitor a good preventative measure or in your experience a waste of time?I have run one for the last 3 years which was due for a flush and inhibitor replacement this year! If it will help, is there a particular one which does what it says in the tin??

 

[bengasman]

I have run one for the last 3 years which was due for a flush and inhibitor replacement this year! If it will help, is there a particular one which does what it says in the tin??

Inhibitor is never due for replacement.
IF the flush is carried out correctly, the system never needs cleaning again for as long as the inhibitor concentration stays high enough.