Relay problem

It's ON-topic for s.e.basics, so no worries on that account. The only OFF-topic questions on s.e.b are those that don't involve electrons in one way or another. ;-)

I'd look at the physical condition of the relay, like dirt or some obstruction; and check all of the connections in the relay's coil circuit. It sounds like it's not pulling in fully.

It used to work, and this symptom appeared recently, right?

Thanks, Rich

Hi, Rich. Always good to hear from you. Nice to see you're spending some time amidst us groundlings on s.e.b.

You're right, it's probably a good idea to look at the physical condition of the relay first. Since it's a heating application, I'd guess it's probably an AC relay, so I'd also suspect a partial short in the coil, or a loose shading ring. Sometimes the shading ring comes loose, and can be snapped back into place.

Less likely, the thermostat or sensor switch driving the relay might not be closing fully, or has gotten resistive.

Best solution might be to replace the relay, and see if that solves the problem. If it doesn't, the solution is probably in the switch or thermostat.

I hope this does something to improve the knowledge : baggage ratio.

Good luck Chris

This could be OT, but I'm posting here to get replies with no baggage.... I have a relay in my boiler which buzzes/arcs I'm trying to diagnose the fault, probably in my wiring. What conditions (eg shorting) would cause a relay to switch on & off very rapidly (leading to a buzzing noise) & arc? Many thanks Jonathan

Oh, puh-leeze! I'm a groundling too, just I've been in the trenches for going on forty years. ;-) (i.e., I've learned the difference from my elbow to a hole in the ground. I made up that expression by incorporating two old cliche's[1], by the way. I've heard it on TeeVee. Anyway....

Admittedly, the accolades make my ego get too big for the cubicle, and it makes me want to dance and shtuff, but please don't gush!

I got a stipend from a benefactor once, (benefactress, actually, but I don't want to be sexist), and when I went to kiss her feet, she said, "Oh, don't grovel!" If you want to find somebody to fawn at the feet of, lurk news:sci.electronics.design for awhile. ;-)

Me, Too! ;-)

Cheers! Rich [1] apostrophe used in lieu of accent grave

Graham & Art wrote, HVAC Technician time, would probably save you a bunch in the long run. Many possibles. Get a heating engineer in to look at it.

Thanks - I am somewhat impecunious at present & also trying to check whether my wiring is at fault or if therelay is defective from new - and therefore who should foot the bill. If I had the cash I would quite happily call an engineer. In fact, if I'd had several grand spare, I would have got a pro to install the whole CH system and save me a lot of time & effort. But I haven't.

Rich Grise wrote: I'd look at the physical condition of the relay, like dirt or some obstruction; and check all of the connections in the relay's coil circuit. It sounds like it's not pulling in fully.

It used to work, and this symptom appeared recently, right?

The boiler & all controls are brand new, so it SHOULDN'T be u/s. No, the arcing was there at the start. I looked at Schrack's website at the spec, hoping the relay was plug-in rather than soldered in directly, but alas not. I can't see into the casing of the relay as it is too small & too crowded. I don't want to go opening stuff up until I know the fault is mine not the boiler manufacturers.