vaillant ecotec plus 831 Filter - is it easy to get to?

2 Feb 2015
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United Kingdom
I have a vaillant ecotec plus 831 and I would like to have a look at the canoe filter -


Do I need to drain the system to have a look at it - Im guessing yes

Is it easy to get to - can I just undo it (left pipe beside pressure sensor)

Thanks in advance

O and whilst Im here - can I just pop out the pressure sensor and stick that back in -or does the system need to be drained for that too
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Don't touch it.

Yes everything will need to be drained

Defending on the model removing the pipe could cause a leak higher up in the hose or hex.

Also I have removed many canoe filters from these boilers. But never in one piece.

What problem are you having? Why would you like to look at the canoe filter?
I have heating and not a lot of hot water - especially at high pressure

I had the plate heat exchanger replaced but they say its the main heat exchanger now - I have read that it could be as simple as this filter being blocked so wanted to just check before another £450 on a power flush
If the filter is blocked the boiler would be noisy (rumbling) during DHW.

What does D.36 say when you run the tap?
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It is noisy

If I have the water on low at the tap I get some water for a bit then it fades away to cold

If I have the tap on full it goes warm for 5 secs then nothing

I have watched the boiler it flames for 10 seconds or so and gives up - also very bad kettling noise

Have had the plate HE changed but I don't think they checked the filter so that's why I'm asking

I put some fernox f5 in and that made the HW run for a bit longer but after 5 days it's bad again

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