Potterton Combi 80 Central Heating Problem

[ttj]

Have a Potterton Combi 80. When the remote stat call for heat the boiler is operating in short burst say comes on for 30 secs goes off comes on again a minute later stays on for 30 secs goes off and so on. Works fine for hot water, pump runs ok
but because the boiler cut off very quick the flow pipes do not get hot enough even the ones inside the boiler can keep hands on them under central heating demand. The rads do get warm eventually.

Can anyone suggest whats wrong is it a sensor, and how I could check to prove that the item is broken or not working as it should.

Help needed.

 

[Billy Bob Bob]

more than likely the room stat is faulty does not sound like boiler as working ok to dhw

 

[ttj]

The remote stat is a new drayton wireless unit, seems to indicate and call for heat ok and idicates flame on the stat as it should
and the green indicator on the receiver indicates that heating is on. But the boiler still works in short burst as described could it be anything else. Can check if stat is faulty by removing it and replacing with wire link.

 

[Billy Bob Bob]

yes what potterton 80 is it? performa?

 

[ttj]

Its an old boiler just Potterton Combi 80 been told its a rebadged puma if that helps.

 

[Puddle]

wax cartridge probably stuck,not opening for heating,leave running over night ,may free off,if not have to replace

 

[Billy Bob Bob]

carefully with mains disconnected loop together wires 3 =4 in the receiver (going from memory that should loop it out do not loop live and neutral together IT WILL EXPLODE

 

[Billy Bob Bob]

carefully with mains disconnected loop together wires 3 =4 in the receiver (going from memory that should loop it out do not loop live and neutral together IT WILL EXPLODE

or as puddle says could be cartridge i hate pumas they are sheds sadly

 

[ttj]

Thanks for the help Guys, have recently replaced the diverter valve, so unless faulty part should be ok. Wished
had chucked the boiler in the bin its a right pile of unrealiable junk. When it works its fine but just too unreliable.

Could it be anything else.

 

[Puddle]

Do you have any dripping taps,if so will not change over to heating,if so,turn cold mains off to boiler and see if heating works

 

[ttj]

Will check them out dont recall any but you never know, will try you tip with cold mains to the boiler, thanks again

 

[ttj]

No tripping taps, would the diverter valve hold off the boiler from working in Central heating mode. Would have thought the boiler would work and then lockout on over heat etc. Can anyone confirm as the diverter valve is only 6 months old.

This morning the stat was calling for heat but the boiler was just not working and all pipework was luke warm. Again DHW works fine, have not checked the stat is working properly, by removing and replacing with link wire.

Any other suggesting on what to look at would be useful.

 

[Puddle]

back to basics

(boiler stoped as pump blowing fuse,replaced now only working on hot watewer,persume you turned power of to boiler and stat when replacing pump...sorry threads mixed up )

check everything calling for heat,check wirless stat does not require resetting and in talking to reciever,
if you have no fan or pump on heating mode,divertor will not get a chance to open

 

[ttj]

Didnt replace pump only diverter valve, pump and fan works fine when using DHW.

 

[gasmarc]

first thing to check is red led light on board on if so you will never get heating as stuck in HW mode, there is a CH thermistor that could be faulty