Potterton Performa 28i

[goz666]

Hiya guys, I went to one of these last friday (second man on job, first one said there was nothing wrong) anyway the boiler runs fine on DHW. When you switch over to Central Heating the demand light comes on, the boiler fires and runs for about 20 secs then goes off along with the demand light, then the demand light comes back on and the process is repeated. There are no fault lights at all on the boiler either, I had a CH sensor with me so I checked it and changed it anyway, flue looks perfect, customer rang me tuesday to say boiler was fine and now tonight they've rang to say its started again...any ideas before I traipse back there !! Thanks.

 

[ambrosia]

1st thought is pump unable to get the heat away fast enough

 

[Ermintrude]

Check diverter is working. Take head off, pull out small plate just below head. Switch between DHW and ch. Pin should move. Also check boot and contacts ok. Check voltage at boot when ch req.

Fault tree at back of book

http://www.partsarena.co.uk/baxi/System/DATA/Dx/DS1/installation/2201/I04-2201/I04-2201.htm

 

[mutley racers]

What a boot

 

[Ermintrude]

What a boot

Boot is the bit that connects power lead to head.

 

[ambrosia]

what is the boot? you guys are talking about stuff i dont know about, i feel left out what is the boot

do you really take diverter valve apart not just visually check whether pin is going in and out

I didnt click on the link but those boilers dont have a pump proving switch do they, those faults which wont happen while youre there and dont lock out usually go back to air pressure switch, pump proving switch or some type of over heating

 

[Leo21]

Edited post Cus I was wrong.

 

[Ermintrude]

I did google it and thought it was same as duo? If same as 105 with diaphragm then yes defo pin. But pin on diaphragm is for DHW? Pin at back is for pump? If 105 variant always suspect diaphragm, microswitch and some times the two micro tubes to either side of diaphragm??

 

[Ermintrude]

what is the boot? you guys are talking about stuff i dont know about, i feel left out what is the boot

do you really take diverter valve apart not just visually check whether pin is going in and out

I didnt click on the link but those boilers dont have a pump proving switch do they, those faults which wont happen while youre there and dont lock out usually go back to air pressure switch, pump proving switch or some type of over heating

Don't take to bits, remove actuator head and see if its actuating!

 

[Leo21]

Actuator head would be my best guess, don't they have to go to there correct position to signal the pcb to operate.

 

[goz666]

Would the actuator head cause the C/H demand light to go on and off ?? I'm losing the demand light and that's causing the burner to drop off. Within seconds the demand light comes back on and the boiler relights, it's not even getting to flame failure !!

 

[Ermintrude]

No would cause boiler to overheat and register no flow. Check stat and if internal clock short the two black wires. Sounds possibly like demand intermittent! Loose connection at stat?

 

[Billy Bob Bob]

I did google it and thought it was same as duo? If same as 105 with diaphragm then yes defo pin. But pin on diaphragm is for DHW? Pin at back is for pump? If 105 variant always suspect diaphragm, microswitch and some times the two micro tubes to either side of diaphragm??

motor will work on a duo,not sure if leads the same,DV as you probably know is totally different

 

[goz666]

No would cause boiler to overheat and register no flow. Check stat and if internal clock short the two black wires. Sounds possibly like demand intermittent! Loose connection at stat?

That's what I'm thinking mate, I thought it was the CH sensor tbh and it's been fine for six days and all of a sudden same fault again. Regarding the back diaphragm I always thought it was to prove the pump on this boiler ??

 

[Ermintrude]

That's what I'm thinking mate, I thought it was the CH sensor tbh and it's been fine for six days and all of a sudden same fault again. Regarding the back diaphragm I always thought it was to prove the pump on this boiler ??

DHW on and off not pump proving

Diverter and 3 pin (boot) and ch prooving. Normally open?

 

[stevetheplumber]

how do you get pics like that on your phone ?and how you get them to here ?

 

[Billy Bob Bob]

how do you get pics like that on your phone ?and how you get them to here ?

was thinking the same

 

[Ermintrude]

You have more post than me gas man so not telling u!

 

[mutley racers]

It's got to be an app

 

[Ermintrude]

I have iPhone, may be different on Htc
Firstly get

Then find pic u need

Then push screen lock and menu button at same time...

Then post as usual

.

iPhone is excellent as u can send pics for free to other I phone users .... So easy when explaining to some one!

We send our parts supplier pic of data badge and the part we want on boiler . He sends back pic of part to confirm with price then posts it. Never speak to him bower days unless bored!

Try him he posts next day anywhere in uk and is cheap! If u want number pm. Don't want to upset any sponsors!

 

[Billy Bob Bob]

You have more post than me gas man so not telling u!

thats ok i can make yours run backwards LOL NOW thats a app

 

[Leo21]

DHW on and off not pump proving

Diverter and 3 pin (boot) and ch prooving. Normally open?

Only 3G pfffft.

 

[Ermintrude]

Only 3G pfffft.

It's the battery that gets on my ****!

 

[mutley racers]

We send our parts supplier pic of data badge and the part we want on boiler . He sends back pic of part to confirm with price then posts it. Never speak to him bower days unless bored!

Try him he posts next day anywhere in uk and is cheap! If u want number pm. Don't want to upset any sponsors![/QUOTE]

Are they new parts or reconditioned

 

[Ermintrude]

No never all genuine new stuff! He knows his stuff used to be big boy at Pts Few years back!

 

[goz666]

I'm pretty sure its an old Performa then the one i've been to because its got the old type diverter valve with a microswitch sat over another diaphragm where the dv head is on your pic. Its defo non condensing !!

 

[goz666]

I'm pretty sure its an old Performa then the one i've been to because its got the old type diverter valve with a microswitch sat over another diaphragm where the dv head is on your pic. Its defo non condensing !!

Am wrong, must be my age catching up with me. Went back last night boiler wouldn't fire at all on DHW or CH, checked all connections back to board for continuity, boiler cycling.... burner lit burner off within seconds.Still no warning lights and still not reaching flame failure, anyway I suspected maybe the gas valve so tapped the top yellow coil and the boiler lit straight away.Tapped it again a few times and the boiler knocked off and back on. So as it was 8.30 last night I've left it running and am thinking of ordering a new coil if possible ??

 

[Leo21]

Am wrong, must be my age catching up with me. Went back last night boiler wouldn't fire at all on DHW or CH, checked all connections back to board for continuity, boiler cycling.... burner lit burner off within seconds.Still no warning lights and still not reaching flame failure, anyway I suspected maybe the gas valve so tapped the top yellow coil and the boiler lit straight away.Tapped it again a few times and the boiler knocked off and back on. So as it was 8.30 last night I've left it running and am thinking of ordering a new coil if possible ??

If it's cycling it's the pcb.

 

[goz666]

If it's cycling it's the pcb.

Have you had this before Leo ?? I thought maybe PCB until I touched the gas valve but yep it's lighting on both DHW and CH and immediately dropping then again cycling. Occasionally stays on and remains on.

 

[Leo21]

Yes I've had it before. If you listen it,ll start, run the fan and then when the aps activates it shuts down and repeats. It will fire like this occasionally. Every time I've had it it's been the pcb. Pm gas man he's the top bloke in these, in sure he,ll agree.

 

[Billy Bob Bob]

Yes I've had it before. If you listen it,ll start, run the fan and then when the aps activates it shuts down and repeats. It will fire like this occasionally. Every time I've had it it's been the pcb. Pm gas man he's the top bloke in these, in sure he,ll agree.

agree probably pcb is failing what i have also seen is water leaks cause similar issues runs down the harness and takes out the pcb

 

[goz666]

Just a quick update, replaced the pcb on monday morning and boiler now all good. Thanks to all