Measuring pipe temperatures on my heating, I notice a convection flow effect driven by the HW cylinder during system idle periods, likely resulting in wastage.
My thought is to put a non return valve between 3W port and cylinder.
Is this suitable for CH??
http://www.screwfix.com/p/15mm-single-check-valve/38236
Also, the space around the tank is awkward. Is braided flexible hose OK for CH use?
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Here is evidence of the convection, with an experiment combining electric and gas heating.
https://drive.google.com/file/d/0B4xffi9ItIebMTN5a0t2cHE5Mzg/edit?usp=sharing
Red is top of HW cylinder, blue is flow pipe.
At 18:00, heat electrically only (about 20 minutes). Causing flow temp to rise.
At 19:00 heat with gas only (about 30 mins). Flow temp drops momentarily, suggesting the pump is changing flow back to the correct direction.
For about an hour into idle, flow temperature drops, as expected, but then rises again. (This dip and rise always occurs after boiler switch off. Definitely not the boiler firing again.)
My thought is to put a non return valve between 3W port and cylinder.
Is this suitable for CH??
http://www.screwfix.com/p/15mm-single-check-valve/38236
Also, the space around the tank is awkward. Is braided flexible hose OK for CH use?
...................................
Here is evidence of the convection, with an experiment combining electric and gas heating.
https://drive.google.com/file/d/0B4xffi9ItIebMTN5a0t2cHE5Mzg/edit?usp=sharing
Red is top of HW cylinder, blue is flow pipe.
At 18:00, heat electrically only (about 20 minutes). Causing flow temp to rise.
At 19:00 heat with gas only (about 30 mins). Flow temp drops momentarily, suggesting the pump is changing flow back to the correct direction.
For about an hour into idle, flow temperature drops, as expected, but then rises again. (This dip and rise always occurs after boiler switch off. Definitely not the boiler firing again.)