When the pump is just the start….

8 02 2009

This post all started from an evening when I was changing the light fitting above my desk (something that you are still allowed to do under EU regulations). Suddenly there was a squawk from downstairs. The TV had gone off. I trouped out to the garage to look at the consumer unit and sure enough the residual current device (RCD) had tripped. (RCD’s are the more modern replacement of ELCB’s.) I didn’t think it had anything to do with me (I had my lighting circuit off), so I reset the switch and everything came back to life.

The next morning I awoke to ominous quiet and cold. Why wasn’t the heating on. I went out to the garage (-1C) in my pyjames and sure enough the RCD had tripped again. It’s amazing how an illogical hunch can throw you off the scent. The RCD was being tripped by the garage and heating circuit, and more specifically, if I turned off the master switch to the heating, I was able to reset the RCD.

I decided the only approach I could take was to disconnect each component in turn (pump, zone valve, boiler, programmer) and after each disconnection, turn on the heating circuit to see if it would go on without tripping the RCD. First was the pump, and bingo. A double check by connecting the pump to a 13amp mains plug and plugging into the upstairs ring main confirmed the diagnosis by instantly tripping the entire circuit. There were telltale signs of damp on the casing. Electricity and moisture are not good bed-fellows.

Having been snowed-in for 2 days (our main car could not get up the icy hill), I got on my bike to a local plumbers’ merchant who was beating the internet prices for an identical replacement pump. Safely home it then took the entire evening to remove the old pump (which was seized on) and fit the new one. ( I used WD 40 then heated up the offending joints with a blow lamp, taking care to distribute the flame all round the joint.  Against the fitting instructions the threads had been liberally coated with something that had dried hard.)

That evening the heating fired up, the programmer turned it off for the night and the following morning it was on when I got up………………..for about 50 minutes. Then it died. For good.

to be continued….




Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: