Servicing a Vent Axia Sentinel Kinetic Plus B - 8 years old unit

[Stones]

Following on from this original topic, I have today just completed the annual main clean and service of my MVHR unit, now 8 years old.

 

With our unit now located within the heated envelope of the house (rather than our cold loft as it was originally), the blocked condensate drain issue has not arisen again.  There is always some evidence of mould growth on the extractor fan blades and extract fan chamber, but given this is a cold and damp / wet part of the unit, that is hardly surprising.  I did however uncover 2 new issues:

 

1. The summer bypass, which consists of a plastic louvered fin assembly in a rectangular frame, opened and closed by a solenoid, was stuck in the closed position, i.e. on summer bypass.  Closer inspection revealed the end of the solenoid which allows the unit to switch from heat recovery to summer bypass had broken off.  On attempting to operate the louvres by hand, they were stuck solid.  The screws securing the louvre assembly to the frame had corroded to such an extent that they prevented movement, which in turn caused the solenoid to break. The screws were so far gone that they dissolved on contact with a screwdriver.  With the gentle persuasion of a mallet, I was able to tap open the louvre assembly to the heat recovery position.  This means that I now have no summer bypass as there is no means to close the louvres.  Not an urgent problem given the time of year, but something I will have to think about getting a replacement part for.  Top tip therefore, lubricate the screws to try and slow / prevent corrosion.

 

2.  Eight years of removing and re-inserting the core has torn / destroyed one of the seals (pictured hanging).  Fortunately, I had some neoprene adhesive backed tape which I used to replace.

 

Other than that, (and a previous fan bearing replacement) the unit is still going strong. 

 

[Stones]

[Russdl]

@Stones thanks for that update/great reminder.
 

Apart from filter changes I’ve not opened mine up yet. It’s been on my ‘to do’ list for a while, as have many things, I’ll put it top of the “things to do when it get warmer” list. We’re only 3 years in so hopefully no big horrors lurking inside. 

[Andehh]

Yep, we're 18 months in ourselves! Interesting points to keep an eye on though.

[Pocster]

Where’s the summer bypass grate ? . I had mine open due to leakage issues and I do t recall seeing anything like that .

[Stones]

At each end of the louvre assembly, the 3 slats you can see closed.  The bypass forms when the solenoid closes the main louvres, and opens the 3 slats at each end.  This prevents air cycling through the heat exchanger by guiding the airflow (with the aide of foam on each end of the heat exchange core) around the heat exchange core.

[DOIGAN]

Hi Stones, interesting that you mention mould on the inside, our unit is covered in it and gets very wet inside, you mentioned the location, ours is in the loft where builders put it, not really an option to move it either, ant suggestions about the mould and how to stop the inside being wet?

Cheers

Andy

[Stones]

On 23/11/2024 at 14:39, DOIGAN said:

Hi Stones, interesting that you mention mould on the inside, our unit is covered in it and gets very wet inside, you mentioned the location, ours is in the loft where builders put it, not really an option to move it either, ant suggestions about the mould and how to stop the inside being wet?

Cheers

Andy

 

Sadly, nothing to offer other than a regular clean and treat the moulded area with bleach.  I find that when I remove the heat exchange core, and angle it over, a fair amount of condensate drains out, but generally this remains free of mould.  The plastic louvre grill tends to have mould grow on it, as do the extract fan blades, so I clean the lot, and make sure the drainage hole and pipe run off is clear and free flowing.  

 

Having measured the temperature of supply air into the house, my unit seems to operate at 90% heat recovery.  Added to that the higher relative humidity and moisture levels, it's perhaps not surprising there is so much condensation - but at least shows the unit is working.