combi - hot water: hot-cold-hot-cold, plate heat ex q...

[jackecole]

in your opinion - in a combi - what is the best way to make sure the plate heat ex is at fault, ie if the h/w runs hot-cold or lukewarm etc?

 

[bengasman]

Check the ntc and voltage on valve coil for correct curve; if both are fine, chances are your system is full of crap.

 

[jackecole]

thanks for your reply bengasman.

I used to feel the flow and return primary pipes to it but as you say eliminate these 2 is the better way.

when you say measure valve coil on GV for correct curve, do you mean check the voltage going to modulating coil is correct, so pcb is sending correct voltage there?

I also check high and low GV settings on modureg if applicable.

 

[Agile]

If the temp differential across the plate is too high then it can only be the pump or a blocked plate.

One wonders why someone who is not gas registered is so interested in the detail of boiler repairs though.

Tony

 

[jackecole]

on the DHW thermistor fault with h/w running hot - cold in that cycle, do you find when you test the thermistor the reading is usually ok, and to test it when the fault just occurs is a bugger?!

how do you know I am not gas safe/reg. Agile?

 

[lukewarmbath]

If the temp differential across the plate is too high then it can only be the pump or a blocked plate.

One wonders why someone who is not gas registered is so interested in the detail of boiler repairs though.

Tony

Because the vast majority of gas disasters are caused by professional qualified gas-safe registered fitters. This forum (and the screwfix one) has many examples of poor workmanship by "professionals". its about time the competant DIYer is given credit for carrying out a superb job, meeting all regs. and with a high standard of workmanship. He doesn't have to work against the clock where "time is money".

lukewarmbath

 

[onlyfitidealboilers]

what are you on about