Ideal response 120- no intermittent hot water

[ssray]

Hi, our plumber has moved said ideal response 120 to our garage, the problem now is that he dose not service these boilers and has reccomended ideal.

The Hot water is intermittent at best, the central heating works fine and the leds for the fan and burner light ok,but the hot water led is not working and it is pot luck to get any.
Is this likely to be a pressure switch or is it more likely to be electronic and not replacable by myself?
Cheers Ray
ps looking at other posts i will switch off the mains before playing around

 

[Paul Barker]

As it's a biflow heat exchanger no diverter valve so flow switch is first suspect. Very easy to prove, run a tap, disconnect electrical connection to flow switch, bridge it, but only when tap runing, no more intermittent problems? Change flow switch.

Differential diagnosis? dhw thermister, dhw overheat stat.

Bear in mind pcb is a known bad one, heat exchanger lasts about 5 years on average. You'll know when it's gone, boiler won't light. On inspection the electrodes will be immeresed in the water that has leaked out of the heat exchanger. Advise new boiler when you reach this fault. If it was already 5 years old I wouldn't have moved it.

 

[ssray]

Thanks paul, i`ll update soon.
Ray

 

[ChrisR]

Measure the actual hot water flow rate. It needs to be quite high, about 3 litres/minute, to make the flow switch operate. If yours isn't there's a cpouple of things you can do about it (apart from the adjuster on the hot water output underneath).

Youcan SEE if the HW flow switch is operating or not. Take the front upper cover off (one screw centre top and it pulls forward/off) then look at the red LED!

 

[ssray]

the 3rd led at the bottom, the domestic hot water one is not coming on.
it has worked intermittantly-but not for me

 

[ChrisR]

Ok, so measure that flow. Though 3 litres a min is definitely not good, you should be getting about 10 litres/minute so it's pretty obvious.

 

[ssray]

It was the flow switch, thanks for all the help.

also shopping around switch price £87 aylesbury-£42 black country it helped that potterton use the same switch and are cheaper than ideal

Thanks again

Ray