Potterton Puma 80 perm ig no hot water !!!!

[Andy fin]

Hello all can any body help with Potterton Puma 80. Central heating works fine but upon turning on the hot water tap the water is hot for a split second and then runs luke warm . Have had the usual low pressure problems before. Any Ideas!!!!!!!!!!!!!

 

[HarrogateGas]

Turn off your heating, let the rads cool (2hours) and see what your hot water is like.


If its only hot when heating is on id suspect the flow switch. If it make no diffence then possibly the wax capsule in the divertor valve sticking open to central heating.


Do the rads heat up when you run a bath, even though the heating is off?

 

[gazthepottertonengineer]

my moneys on micro switch faulty or hot water pressure differential check to see if red light comes on pcb when you turn hot tap on

 

[Andy fin]

Did what u said allowed for cooldown and water is still luke warm and pressure of water is low. Ran bath with no heating on and radiators did not get warm. Would you say it is the diverter valve ? is there any othe way of proving it? can it be freed up?

Thanks AF

 

[Andy fin]

Just saw you message gaz yes the modulator board led is lighting up when hot water tap is turned on, Which micro switch would you suggest and where is it located, can I test ! I Have got the original installation manual that came with bolier. in which i can relate to on diagram

Thanks Af

 

[Softus]

Try this test:

1. Turn on central heating.
2. Observe the height of the flames at the burner.
3. Open a hot tap until the slow switch operates.
4. Observe the height of the flames now.

If the flame height has changed, I would suspect the divertor valve wax capsule.

If the flame height has not changed, then I would suspect the gas valve and the PCB. Repeat the above while monitoring the supply voltage to the gas valve DHW solenoid. If voltage present and correct then replace the gas valve, if not then replace the PCB.

 

[ChrisR]

while monitoring the supply voltage to the gas valve DHW solenoid. If voltage present and correct then replace the gas valve

The DHW solenoid, hmmm!
Don't think of replacing your own gas valve.

Diverter stuck in CH mode? Let it cool, turn HW on, feel the pipes once you've determined which is which. M.I. at partsarena.com/baxi

 

[Softus]

The DHW solenoid, hmmm!

Yup - GV3; the one that should have a resistance of 120 Ohms.

 

[Andy fin]

After futhur investigation that it seems to be the mod board. Every time i tap the hot water relay on board i get hot water! Does anybody know where I can pick up a board from at a reasonable price ! It Is listed as potterton part no 929685 Gas council No 289550 (Piolot version)

Thanks Af

 

[Mikeyboy]

Ebay.

 

[kevplumb]

e mail chris r he might have one

 

[Softus]

After futhur investigation that it seems to be the mod board. Every time i tap the hot water relay on board i get hot water!

It's quite likely that you're suffering from a common problem with early Puma PCBs, which is dry joints. Basic re-soldering skills will correct this kind of problem.

If you remove the board and examine the solder joints for the suspect relay, using good eyesight and a strong torch, then you might get a pleasant surprise.

Isolate electrically before opening the boiler casing.

 

[Andy fin]

Have been all over board found a few dodgy joints but still have same problem have even removed relays and sprayed them with switch cleaner as were pitted. The only way to get the relay to enegize is to tap it, i thinks its time for a new board. Have just had a look on ebay and have spotted one lets hope they have a buy price!

MAny THanks Af