Potterton PRT2 Fault?

[petchy]

Hi,

Just had a problem with a newer model of pcb replaced on our potterton suprima 40 .... HW works now as soon as you turn it on however now
the only issue i have is when i turn the heating on ... the heating wont and doesnt come on until i turn the room thermostat down to reached (i.e.5oc) and then up (i.e.20oc) then it comes straight on .... any ideas??

Thanks

 

[nickso]

prt2's can be dodgy.

you dont have a myson powerhead, mpe322, do you? they can be dodgy too.

if you dont have the equipment to fault find i would simply bypass the prt2 and see if the fault persists.

 

[petchy]

No we dont have a myson powerhead, mpe322 ! though im not sure what we have got!

how do we bypass it?

do yoi think its worth buying another prt2?

 

[nickso]

No we dont have a myson powerhead, mpe322 ! though im not sure what we have got!

how do we bypass it?

do yoi think its worth buying another prt2?

no i wouldnt buy another one, thats throwing money away. far better products on the market.

there will be 3 wires inside the prt2. one will be the neutral. if a sparky wired it the neutral will be blue. if a heating monkey wired it it could be anything. whatever the neutral is, ignore it and join the other 2 together and thats it bypassed.

 

[petchy]

so i assume then by doing this when the heating is turned on the thermostat would be bypassed and the ch come straight on?

Within the prt2 the wires are as follows

2 3 4 5

Com H TL N

Brown Yellow Red Blue


sorry and just to confirm we DO have a myson powerhead, mpe322 - its setting is set to auto if that makes any difference?

 

[nickso]

so i assume then by doing this when the heating is turned on the thermostat would be bypassed and the ch come straight on?

Within the prt2 the wires are as follows

2 3 4 5

Com H TL N

Brown Yellow Red Blue


sorry and just to confirm we DO have a myson powerhead, mpe322 - its setting is set to auto if that makes any difference?

cant remember off the top of my head but i think its com and h you need.

take off the screws on the mpe322 and the head can be lifted off. check the spindle below can move properly, they are bad for leaking or sticking. also check the right lights are on depending what you have selected on the clock as the head can also fail.

 

[petchy]

See when i turn the CH on .... the mpe322 light doesnt come on to say CH... i have to go to the prt2 to turn it down and then up ... the light on the mpe322 then comes on then the boiler kicks in and ch comes on .... any ideas?

 

[nickso]

its probably the prt2 then.

 

[petchy]

would i be best to get another prt2? or would you recommend any other makes/models .... bearing in mind what existing wiring we currently have with with prt2

 

[nickso]

im not sure they even make the prt2 anymore.

 

[petchy]

i can find some knocking about on the net for £20 ish ... any recommendations for other stats??