Potterton Netaheat HW PRT2 constantly tripping

[spt19]

Hello,

I have an issue with my Potterton Netaheat boiler which I am hoping somebody has come accross before. It's 18 years old and a gravity fed system using an ep2001 controller with PRT2 thermostats for CH & HW.

Recently the thermostat for the HW is tripping for about 1 min deciding whether to switch on or off when water requires heating to thermostat setting & eventually gets there.
This can also be heard on the boiler as it is getting the signal to switch on and off. It switches initially and then constantly clicks on & off rapidly. You can also see the red & green light changing on the thermostat.

You can stop it straight away by altering the setting on the thermostat either up or down and it willl act accordingly or wait for it to sort otself out. It only happens now and again and the system works fine but I was wondering whether it is best to replace the PRT2 thermostat?

 

[ChrisR]

Yes I can guess what's wrong with its electronics - age and heat take their toll. Unless you want tot go into the electronics, change it.
(Electrolytic smoothing capacitor dried up)

 

[spt19]

Thank's for the quick reply.

I thought it might be that. I saw that you had a similar issue from the posts but I did not see what you actually did in the end.
You can pick up the same hot water thermostats for around £20/25 from what I see on the net so it's easier to buy another rather than take it apart.

Cheers

The 'Electrolytic smoothing capacitor' you mention. Is this in the main thermostat or part of the probe that attaches to the hot water cylinder?