Urgent MVHR help needed

[MJNewton]

31 minutes ago, PeterW said:

It was working before though ..? If it has worked then unlikely to be a wire as it wouldn’t have worked previously as you said.

 

Loose connections can often only cause a problem when power is removed as arcing tarnishes the mating surfaces which increases the resistance of the connection (or disconnects them entirely). 

 

I'd suggest temporarily connecting the control panel directly to the MVHR unit as this would eliminate a variety of potential causes. 

Edited November 20, 2019 by MJNewton

[PeterW]

16 minutes ago, MJNewton said:

 

Loose connections can often only cause a problem when power is removed as arcing tarnishes the mating surfaces which increases the resistance of the connection (or disconnects them entirely). 

 

I'd suggest temporarily connecting the control panel directly to the MVHR unit as this would eliminate a variety of potential causes. 

Agree however that’s on power connections - this is ModBUS so will be 3.3/5v and mA connections which are unlikely to cause a disconnection of this type. 

 

Assuming it is a 2 wire connection then just connecting and reconnecting should clear that. 

[Gone West]

@vivienz Have you had a resolution to your problem?

[vivienz]

1 hour ago, PeterStarck said:

@vivienz Have you had a resolution to your problem?

 

Sort of. It does seem to be some sort of electronics problem and the manufacturer is sending a load of spares out on Monday so that I can get my electrician to swap them around and see if this works. It has taken much longer than I would like but this is largely due to issues with the original installer, both for me and the unit manufacturer, which needed working around.

Edited November 29, 2019 by vivienz
sp.

[vivienz]

Update

 

My MVHR is fixed now, finally. Earthsave sent out a load of spare components and my electrician came out.

 

We had already spotted a loose wire in the box that sniffs the air, situated between the control pad and the unit. Using the Occam's razor theory and rather than go through a lengthy replacement procedure we decided to try this multi-strand connection first. 5 minutes later, all was well and the humidity in the house is falling nicely.

 

Here's a photo of the offending loose wire, it's the yellow one. I'm not at all sure that the fault was related to the power cut, but coincidental and vibration from the staircase caused something that was barely attached to finally pop out.

Edited December 12, 2019 by vivienz
photo

[Simplysimon]

isn't it a relief when it's something nice and easy?

[Savage87]

I had a similar situation with the PIR sensor for my stair lights. I have ordered another sensor so I can replace it and the new one was came from Germany and it was faulty. It took me about 1 hour to figure out that the new one not working.

The old one had just a a loose wire with I had so solder back on and 5 minutes later everything was back to normal. Wife is happy