Am thinking...plate heat exchanger gone blocked?

[mutley racers]

Hi fellers, I have just had a call from a client who has a potterton performa 24. She says her hot water only gets warm and the boiler stops and starts when in hot water mode. Its ok in the central heating mode.

So, I am thinking a blocked up heat exchanger. Now, is it worth me buying the heat exchanger before looking at the boiler and replacing? Or, should i check it out and test the stats?

Thanks guys

[snowhead]

Check it out first, could be something silly, flow switch / transducer failing maybe?

[dave1]

Check the ntc I've found these are good for going, also definatly worth taking the plated off and checking they are easy enough to get out.

[mutley racers]

I think i shall just go without ordering the heat exchanger and take the one out and give it a wack to see if any scale falls out

[gas man]

I think i shall just go without ordering the heat exchanger and take the one out and give it a wack to see if any scale falls out

could be a failing dhw dipragm,diverter valve,blocked phex so no i would not just order one, unlikely to be a thermistor most 24 kw performas dont have one on dhw only the eco,s

[splinterdream]

Snowman, what's a transducer?

[mutley racers]

I did see a post on here a while back and the guy had the same problem. Someone told him to take the heat phex out and whack it a few times. He did and scale fell out and hey presto. All was fine

[mutley racers]

Here is the link...http://www.ukplumbersforums.co.uk/ce...ma-28-a-2.html (hot water cutting out! performa 28)

This sounds exactly like the problem I have

[gas man]

Here is the link...http://www.ukplumbersforums.co.uk/ce...ma-28-a-2.html (hot water cutting out! performa 28)

This sounds exactly like the problem I have

and all 3 of the parts i posted up will give the same symptoms,you wanna buy a plate go ahead it could be the fault,then again it could be a 10 quid diaphragm kit,you wont know until you visit,if its a blocked phex it will be dumping down as well

[mutley racers]

All the guys who helped this guy have all but disappeared. Am sure there are a few I have wondered where they went. Where is unguided by the way?

[mutley racers]

dumping into the central heating side Gasman? i am definitely not going to buy it. Does anyone buy their stuff from Euro Boiler Parts? If so, are they any good?

[gas man]

dumping into the central heating side Gasman? i am definitely not going to buy it. Does anyone buy their stuff from Euro Boiler Parts? If so, are they any good?

flowpipe getting hot or rads warming up when running a hot tap thats dumping down yes euro boiler parts formally abkot are cheap but totally crap with in warranty claims very unprofessional IMHO

[mutley racers]

thanks gasman. I really need to find a decent spares supplier. Not many have the parts you need on the day you need them hey

[zeebeedee]

flowpipe getting hot or rads warming up when running a hot tap thats dumping down yes euro boiler parts formally abkot are cheap but totally crap with in warranty claims very unprofessional IMHO

Do all boilers dump down or only certain ones?

[R1CKY]

Do all boilers dump down or only certain ones?

Depends on the condition of the diverter valve, new ones will resist heat tracing through to the heating flow, where as an old diverter valve with worn springs and seals will allow heat to pass by if the PHEX is blocked.

The way I try and determine whether the PHEX is blocked, is where possible, feel the flow and return from the primary heat exchanger, if the flow is untouchable and the return is noticeably cooler, the PHEX is likely at fault.

I have on several occasions cleaned partially blocked PHEXs by removing them and blasting the primary ports back and forth with an outside tap. Quite satisfying when you see little black lumps flying out.