Servicing a Vent Axia Sentinel Kinetic BH - Mould ...

[gregcope]

Hi All,

Thought I would share my DIY MVHR challengettes.

Unit has run fine for two and a half years.   I have regularly changed the filters and inspected the unit.   The condensate drain was a pipe that poked out of the roof / wall interface, next to the heating/water overflow.  It froze last year in -10C weather so I switched it to drain into an internal soil stack vent.   It is now very well insulated.  I view this as an install issue, not a unit problem.

 

This December I found a small watch patch under the front and rear covers.   I removed the front cover and could not find where the liquid was from.   The internal of the unit PCB area was dry.   I removed the condensate drain bung and some condensate came out with little black specks of dirt.

I stripped the unit and cleaned the heat exchanger in the shower.  It was pretty clean.  Some small specks of dust came out.   The Summer By pass has dirt on it.   I removed this, stripped and cleaned it.

The condensate drain is situated under the Summer Bypass unit.   It was black / dirty.   I gave it a clean but could not get it clean.   I stripped the condensate drain and cleaned that, including its non-return vent which had some little fluf.

I poured some water in and it seemed to drain okay.   Reassembled unit ...

 

Over the next few days it seemed to get better and then worse.   A smaller puddle...

I removed the HE and used some HG Mould Remover Foam Spray (they do a few different ones).   Within seconds this had cleaned the condensate drain area of dark mould.   I also removed the drain and blew into the unit ... I am sure I felt some back pressure and a pop as if it was blocked internally.   I then rinsed and dowsed it in Milton...   I believe the condensate drain was blocked internally and hence the condensate was pooling in the unit and overflowing down the inside of the front and rear covers which drain under the unit.

 

Reassembled and its seems to have dried out and is working.

I think this happened as small amounts of dirt are getting past the filters and with some other biological agents like mould are congregating in the condensate drain area under the Summer bypass unit.

For future I will give it a regular dowse of Milton and check under the Summer Bypass.   I am also checking my filters are a tight fit to reduce the amount of dirt bypassing the house extract.

It was interesting dissembling the unit.  It is built down to a price!   The condensate drain is very small.  The drain is 4mm x 5mm under the Summer bypass unit that then has a 90deg bend somewhere underneath before it meets the round 20mm condensate drain that you plumb the flexible drain tube to.   This makes it hard to clean as I could not poke a pipe cleaner down the condensate drain and see it appear in the round drain tube.   In conclusion its easily blocked by dust/mould.

 

To be fair to Vent Axia I emailed them and had a reply with some ideas two days later.   Most of them were simplistic, but one was to check / clean the drain.

 

[gregcope]

Some pictures

 

top is now

middle is black mouldy goop

bottom is puddle…

 

White thing is an old duvet for insulation!   Don’t judge!

 

 

Edited December 11, 2023 by gregcope