After  installing our HP a year ago and it running well throughout last winter, I thought Id run it up over the weekend after a few months shutdown. It started and ran fine and I shut it down after a few hours then went to check the magnetic filter. Found the filter with quite a bit of flaky debris stuck to the magnetic tube. I don't know whether the debris accumulated through last winter or came from the weekends test run. There was more debris this time than any of the half dozen filter cleans/checks I did in the weeks after installation last year, so glad I checked it.

 

After getting only minimal debris in the weeks after install, I was quite surprised how much flaky grot was in there!

 

Our system is 90% rads so maybe we're going to see more debris than an UFH system, even with inhibitor, but worth checking any filters in your system to make sure they're clear.

12 hours ago, Dillsue said:

worth checking any filters in your system to make sure they're clear.

Probably best to check them at the end of the heating season, rather than the beginning of the new heating system.

The thing with inhibitors is they deplete, a static system will locally deplete the inhibitor and you may get some corrosion.

 

Enable the pump any seize and it will run the pump a couple of minutes every week or so.

Pump anti seize is enabled. I can't remember exactly how often it operates but the couple of minutes a week rings a bell.

On 06/09/2026 at 21:12, Dillsue said:

Our system is 90% rads so maybe we're going to see more debris than an UFH system, even with inhibitor, but worth checking any filters in your system to make sure they're clear.

 

Had a service visit from Vaillant two weeks ago. He didn't find much in the filter (Adey Magnaclean HP) but didn't like the mesh size and said we ought to have inline strainers as well, as per Vaillant schematic. Last year's man didn't make any comment on this.

 

I agreed it is a bit coarse (like a giant kettle fur collector but coarser) but said I didn't want to cut into pipe to add more fittings. He muttered about replacing blocked HX could cost >£1k and not covered by warranty.

 

Previous oil boiler system had been cleaned with Fernox citric acid cleaner and their inhibitor used, always stayed nice and clean. HP installers used Adey inhibitor and biocide.

 

IMO making sure the pH and inhibitor concentration are correct is best way of ensuring trouble-free operation, I have pH testing drops, man claims to have checked Adey inhibitor but I don't know what he used, what do other ppl do?

33 minutes ago, sharpener said:

didn't like the mesh size and said we ought to have inline strainers as well

Most manufacturers have statements saying you must fit a given strainer size to keep your warranty.

1 hour ago, JohnMo said:

Most manufacturers have statements saying you must fit a given strainer size to keep your warranty.

 

Well on the one hand the custom schematic for my system shows a strainer, but then all V schematics I have seen do. OTOH my installers are V approved ppl so I could reasonably assume they knew what to fit, and I preferred the idea of a big mag filter at waist height in the plant room to a smaller inline strainer outside nr ground level. Also as less likely to clog on account of the much larger surface area.

 

And I reasonably assumed that an Adey HP filter would be suitable for commonly used HPs if not expressly approved by V themselves - though to me it does look on the coarse side. Lastly it seems to be a personal view this year's man has expressed.

 

Since in the two years since installation there has been next to nothing in the strainer and the flow rate is still a high as when it was first installed I am inclined to the view that if it is not broke don't attempt to fix it, there is plenty of other house maintenance I can be doing weather permitting.

 

FWIW I would still be interested to know how to test the concentration of the Adey inhibitor without buying their dedicated kit for £64.09, I am not impressed by just having had to pay £20 for their two spare O-rings which the man also suggested having to hand.

 

 

Edited September 10Sep 10 by sharpener