Gloworm compact 80e like worm hot water

[5544]

Customer complaining on Luke warm hot water. On arrival checked for diverter valve problems. Seemed ok.
Plated heat exchanger had been changed two years ago so ruled that out for now.
Checked gas rate of meter with hot water demand,, that was fine at 21mbars.
Then with water control up high checked burner gas pressure. Book said 15mbars, actual on boiler being 10mbars. I checked it from initial demand, the manometer did not go to 15 then modulate down, it just went to 10 and stayed there. So, that is obviously the reason.
Gas valve resistances fine and so was hot water resistance at specific temps. The only way to get the water to get hot was to reduce flow.

I have read that this is a pcb issue. Opinions please, (they are 210.00 after tax!).

 

[easyflow]

Before you spend that sort of money on a PCB I would do some more checks on the diveter valve, This is motor driven, try taking the motor off its housing and turn the hot water tap on and off to see if the shaft in the centre of motor moves in and out and the motor vibrates.
If this checks out ok theres a pin in the diverter valve motor side, try pushing this in a few times, its sprung loaded so quite tough I use a 15mm copper end cap on my finger to get the power,
Sounds like to me the diverter is partially stuck in the heating position and needs freeing off because even with the gas rate you have described you would get more than luke warm water at a steady flow rate.

 

[ukrobj]

Customer complaining on Luke warm hot water. On arrival checked for diverter valve problems. Seemed ok.
Plated heat exchanger had been changed two years ago so ruled that out for now.

2 years is a long time especially if the system is dirty! Without removal and visually checking I wouldn't rule it out just yet.

 

[ZZ44]

I've had this on our Compact 80. The fault was on the PCB. If you look at the PCB, the area to the right hand side of the transformer is discoloured, where components have got warm over time. There is an electrolytic capacitor which dries out, C105. I changed this and got another 2 years out of the PCB before the transformer TR100 then failed. Pity there are no circuit diagrams on the net, it would make fault finding on the PCB easier. We also had to restrict the flow of the hot tap to get hot water out of the boiler, and the pressure was down at 10, not 15, so i does sound the same.