Energy Stats with heatpump

We very rarely get the immersion heater coming on, so I think the pump is sized pretty well… Actually, we had the wrong collectors installed in the early days, and the immersion was coming on all the time, installers admitted the fault and replaced with bore-holes. Now hardly ever comes on unless very-very cold.

There’s no indication at all that the immersion is coming on now, but I am using a lot of electricity when the pump is active and I have this strange 80-90Deg measurement on the collector return pipe. However, I would say that I have put an external Temp probe on the actual flow out pipe - using EmonPI - and that looks about right - ie, 3-4degrees below the flow in.

I have also just set the additional heat to be only 3Kw rather than the 9Kw. There was a setting to set to 3Kw, 6Kw or 9Kw.

All very strange!

Since it seems to have three immersion settings, then most likely 3 relays. And it seems that you are using more than you should. Are you sure one of your relays have not arc closed? Or maybe from your earlier description of your earlier problem your installer did not try to bamboozle you and hard wire it, just to give the impression that it was not coming on, to satisfy your earlier concerns? What was the compressor’s usage compared to total usage?

Thanks Steve, how can I tell if > one of your relays have not arc closed?

Should that be clear inside my heat pump? Also, how do i tell what the compressor usage is - i guess i need to put a elec monitor on the compressor power connection?

(sorry if being dim, just not an electricity wizz :wink:

if you have a simple amp meter just put it on one of your compressor power line . when it running read the amps multiply it by your local voltage and you have your wattage , compare it to your emon usage and see if there much of a difference… ( they are not that much ~ $20 for cheap one )

if you have a great difference, in what emon reporting then most likely a stuck relay., if you can locate your relays, generally just tapping them lightly with a screwdriver handle when it not running will usually cause them to release and you generally will hear a click. you can decide if you need to replace the relay if you want, if it a sticky one. but sometimes they may never stick again- i would just wait to see how frequently it sticks before replacing it ( or you can take it apart an file the points off the burs)… if your installer jumpered it. then usually you will see a wire that looks totally out of place. but then again that comes down to how comfortable you are working with electricity. and what you do next, if you can not figure out if it a sticky relay or a jumpered one – would not want to see you accidentally electrocute yourself.

The British term is “welded”.

You should not have a welded relay if it has been correctly specified for the load that’s been connected. Two 'if’s there: the manufacturer got it wrong (cheapened it), or the more likely reason is if the load is outside the specified rating: too big or too inductive. if that’s the case, replacing like for like will get you going, the long-term cure is to replace the relay with one that’s more appropriate for the load.

thanks both - i’ll monitor over the weekend and see what’s up