Clearing strainer on Danfoss Termix VVX-B

[KaraB]

Hi all,

 

I live in a flat with on a green development - the property has a central biomass system with a heat exchanger in my flat. Unfortunately (from what I've been told), when the system was commissioned the pipework wasn't flushed out correctly. Due to this, the strainer in the hot water unit in my flat regularly builds up with crap and reduces its effectiveness, meaning taps and shower can only run hot for a minute or so before going lukewarm/cold.

 

Recently it's been happening more and more often, three times between about July and December and now it's been playing up again in recent weeks. I contact the landlady, wait a week or more with cold water, a plumber or heating engineer comes in with little but an adjustable spanner and a plastic jug, shows me all the crap that was in the strainer and leaves 5 minutes later.

 

I also have an adjustable spanner and a plastic jug...

 

Could anybody tell me what the steps would be for clearing this? Presumably it's a case of isolating the water supply, clearing the strainer then bleeding the system. I know where the the strainer is, but not sure how to do the others. I've attached some images, let me know if any more would be helpful.

 

If the overwhelming consensus is to just suck it up and wait for the professional to do it then fair enough!

 

Many thanks for any help

[TonyT]

https://stockshed.uk/files/danfoss-redan/Installation_Termix_VVX-B.pdf
 

page 15

[KaraB]

Thanks Tony - the question was more about which valves need to be closed in advance of removing the y-strainer cap, and whether the system needs to be bled afterwards. There are no valves inline near the strainer, they're all at the top of the unit as far as I can see. Any ideas?

Edited February 13, 2021 by KaraB

[TonyT]

The strainer is on the return of the heating, so I don’t know which valves  do what on that set up, no harm in isolating all 4 removing the strainer and cleaning it.