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Dodgy Vaillant ASHP foundation & Eddi Diverter Making Central Heating Water Dirty
@jennyross I like your descriptions, they're helpful. Sounds like metal deposits to me. It's not uncommon to find some in most systems tbh. Are you finding that this is causing any issues like high running costs, or perhaps flow faults that stop your heat pump running? Or was it mainly the engineer telling you that it was a problem?
You might consider asking the next maintenance engineer to run through the process of cleaning the filters with you so you can potentially do it yourself another time.
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@sune thank you. I’ll labour on with layperson’s descriptions then 😅
I don’t think the running costs have been higher in recent months. The installer showed me the HW tank filter blocked with ferrous (thanks toodles) material which he said was a problem.
if this is likely to be the result if the filters haven’t been cleaned or replaced at service, then maybe it’s built up over the last year?
@jennyross a totally blocked filter will stop the heat pump from working (it would give a "flow fault") so I guess that wasn't happening. And it's good that it was doing its job and protecting some of the narrow water pathways in the heat pump from that crud which is why its there. You would likely expect some dirt there, as you would with most types of filter really.
If it was my system I'd be tempted to have a look at the filter again in a few weeks, check how much it had caught (and give it a clean), then use that to get some sort of idea of how much rubbish is in the system and whether additional action is a good idea.....or not. Checking and cleaning a filter isn't a highly technical job nor is it specific just to heat pump systems - really any heating engineer should be able to do that, or indeed a competent homeowner as long as they know the simple steps required.
I wouldn't expect much more detritus to build up in the summer as you'll probably have the heating off - so the heat pump only has a very short and simple pipe run to and from your water cylinder - there shouldn't be a significant source of detritus there.
When you turn on the heating though then the rads are part of that water circuit - and that's probably where it came from/is coming from. So perhaps also a good idea to check that filter once the heating has been on for a couple of weeks later in the year. It might well also be that you have not much of a problem at all!
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