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Back boiler not heating properly

skyfella Member Posts: 1
Hi All,
I hope I may be able to get some help with the issue I am having with my system.

I have a 20Kw log burner with back boiler (Kratki Lucy 20) which is feeding my 300L Thermal store (Advanced appliances SFUTS ).

The Store and the burner are around 25m (75ft) apart and have a 28mm copper feed and return, but it does not seem to be producing anywhere near enough heat in the water.

One issue that I have found is that the SFUTS instructions described the boiler heating flow and return in such a way that I misunderstood that the flow was into the store and return was to the burner, and assumed the flow was to the boiler and return from the same, so this means that I have cold water entering the top of the burner and the hot coming out the lower output.

The question is, would the flow and return being this way around(it is not explicitly described as to which way it should be configured) cause the water to leave the back boiler at a temperature lower than one would expect, or am I maybe looking for a different issue?

I hope somebody could throw me a few Ideas as it is doing my head in.

My first thought is to reverse the flow pump, but I'm not sure how that would effect the blending valve. This is just to prove it is the issue before having to drain the system to redirect the in/out...

Any thoughts?


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Why not just fix it and pipe it the way the manufacturer want you to?
  • ThomasM84
    ThomasM84 Member Posts: 7
    I'd go with it and reverse the flow pump.