Wet UFH Temp Question
Discussion
I have an Ideal Vogue C40 combi boiler and UFH throughout my house.
I’ve been running the boiler heating temp at around 50 for the last year and blending to 40 at the manifold.
I recently had a boiler service and the engineer suggested running the boiler hotter for better efficiency. This means I have to alter the blending to get back to 40 at the manifold (it went up to about 60 when the boiler temp was changed).
So the question is this,
- is it better to run the boiler hotter (but supposedly more efficient) and blend down more (which to me would be defeating the point of extra heat output from the boiler)
OR
- is it better to minimise the blending required at the manifold with a lower water temperature from the boiler?
Slightly confused!!
I’ve been running the boiler heating temp at around 50 for the last year and blending to 40 at the manifold.
I recently had a boiler service and the engineer suggested running the boiler hotter for better efficiency. This means I have to alter the blending to get back to 40 at the manifold (it went up to about 60 when the boiler temp was changed).
So the question is this,
- is it better to run the boiler hotter (but supposedly more efficient) and blend down more (which to me would be defeating the point of extra heat output from the boiler)
OR
- is it better to minimise the blending required at the manifold with a lower water temperature from the boiler?
Slightly confused!!
Jeremy-75qq8 said:
My understanding is today's engineer is correct.
The boiler is more efficient at high temps and allows it to condense properly. Also better for heating hot water.
As long as you can mix it down to 35/40 will be fine.
I'd say the opposite. The hot water and heating flow temperature are separate so keeping the heating flow at 50 won't affect the hot water temp.The boiler is more efficient at high temps and allows it to condense properly. Also better for heating hot water.
As long as you can mix it down to 35/40 will be fine.
Boiler are more efficient at lower temperatures. They will work in condensing mode when the return temp is below 55 C.
Keep it at 50 OP.
Jeremy-75qq8 said:
My understanding is today's engineer is correct.
The boiler is more efficient at high temps and allows it to condense properly. Also better for heating hot water.
As long as you can mix it down to 35/40 will be fine.
Maybe this will helpThe boiler is more efficient at high temps and allows it to condense properly. Also better for heating hot water.
As long as you can mix it down to 35/40 will be fine.
Return temp is the scale along the bottom
Boiler Efficiency is the scale up the vertical
The lower the return temp is below 55 deg C the higher the efficiency in a condensing boiler
If return temp is above 55 Deg there is no "benefit" from condensing because it doesn't (warm up phase from cold excluded)
DoubleSix said:
This is topical for me.
My bypass valve is permanently activated sending hot water back to the boiler would this mean my boiler isn t condensing and is therefore highly inefficient?
What's your flow temp?My bypass valve is permanently activated sending hot water back to the boiler would this mean my boiler isn t condensing and is therefore highly inefficient?
Assuming the bypass isn't returning everything back to the boiler or you wouldn't be getting any heat?
OITS will say sometimes a little bypass isn't a bad thing and he's not wrong but it is system dependant
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