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May 1, 2019
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Hi

I wonder if anyone can help with a central heating issue. I have a 7 year old house with Ideal Logic Heat 15 Boiler - this runs central heating and hot water system.

Over the past few months I notice the boiler running then cutting out and restarting quite a lot, after 15 minutes of doing this, it stops running and flashes the F/A code for a while before restarting again.

This happens when running CH, Water or both at same time.

It appears this is due to water running the wrong way round, now the pumps have never been changed or fiddled with and it did not originally do this. I have measured temps on the flow (right) and return (left) on the boiler, and the return is consistently approx 15 degrees lower temp (am running pump in medium speed).

To me, this shows that flow is correct, and if anything whatever is giving the temps to the boiler is wrong. Is it likely that the flow/return thermistors are faulty or am I barking up the wrong tree?

I had a recommended heating guy round, but to be honest he seemed lost and only wanting to do basic stuff, finding a fault in this didn’t interest him and he never returned after apparently speaking with Ideal.

Thanks in advance for any help...

Craig
 
low flow / not getting the heat away

By the way, hot water and heating both get up to temperature ok, and work fine otherwise, just with the slight delays while shutting down with this code for a bit.

Flow approx 55 degrees, return low 40’s?
 
Pump on the way out or blockage somewhere restricting flow is usual culprits.
If new build of about 7 years ago poss a grundfos alpha 2 pump in set up which don't seem to be as robust as the old selectric variants.
Check pump for rotation if you know what you are doing or get plumber in who is gas safe registered so they can look into boiler side if necessary,
Thanks,
Andy
 
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