Potterton Proforma 28I crcuit diagrams Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[mulhaird]

Does anybody know where I can get a circuit diagram of the PCB in the above boiler. The PCB was replaced a few months ago. Everything is working but the hot water temp coming out of the tap does not equate to the temp the boiler shows. The water is about 40degrees yet the boiler says its 70. Variation in the temp of the I/C mains has no effect on this. There is a small variable resistor on the PCB and I was wondering if this set the temp of the water.

Any ideas?

[htg engineer]

Do you not have the boiler instruction manual ? the wiring diagram will be in there.

If you don't have the instruction manual it's worth getting one, a CORGI registered installer shouldn't work on any appliance without having the manufacturers instructions.

Or you may find the diagram on the inside of the boiler case.

Proforma ???? or Performa

[mulhaird]

I have the schematic diagrams but not the electronic circuit diagram of the PCB. Ever since the gas board replaced the original one which they blew up the system does not modulate the hot water. The water is fine when the heating is on but when off its takes ages to warm up from stone cold. Before they got their hands on it the hot water was always warm. The boiler would switch on automatically and warm the water in the primary circuit so we virtually had instant hot water.

[htg engineer]

The performa 28i - the istands for instant - is there a pre-heat setting on your boiler controls ?

They have probably fitted a circuit board for a potterton performa without the pre-heat, you can use a PCB for a potterton combi in the 28i but you lose the pre-heat option - you can't fit a PCB for the 28i into a normal combi.

Get them back, and explain the fault - I'm 99% sure they would have fitted the wrong PCB.

[mulhaird]

Thanks for this.. Thay are coming back Monday afternoon. I will let you know what happens.

Dennis

[mulhaird]

The gas man came back. Apparently when the PCB was replaced he failed to fit the pre-heating jumpers. These have been re-ordered and he will return and fit them tomorrow.