Calorifier losing heat to engine!

Oily Rag

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My Beta has the usual connections to the calorifier to produce hot water. But the engine is slightly above the calorifier, so when the engine is shut down, the calorifier sends a reverse flow to the engine. It keeps it lukewarm overnight but leaves the water rather tepid in the morning.

Can anyone recommend a spring loaded non return valve for fitting into the pipe work from the engine? I'm thinking of something from a plumbers merchant that could be fitted to 16mm/5/8" heater hose.
 

plumbob

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Usually? There would be 2 lever ball valves on the flow and return to the calorifier. Best way is to turn them off when not running the engine to effectively stop thermal syphoning. Potential trouble with a non return valve in the pipeline is if the resistance is too great obviously the flow rate will decrease. I use the kiss principle.
 

Boater Sam

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All you need is a loop in one or both hoses to the calorifier higher than the top of the engine to stop the gravity circulation.
If the hose is the high point rather than the engine you will have no problem.
Conversely taking the hoses as low as possible near the calorifier, lower than the coil connections, will do the same job,
 

Plum

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All you need is a loop in one or both hoses to the calorifier higher than the top of the engine to stop the gravity circulation.
If the hose is the high point rather than the engine you will have no problem.
Conversely taking the hoses as low as possible near the calorifier, lower than the coil connections, will do the same job,
I have found that if you make the loop higher you will get an airlock which can stop the water circulating when the engine is running so your second option would be my recommendation.

ww.solocoastalsailing.co.uk
 

Plum

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My Beta has the usual connections to the calorifier to produce hot water. But the engine is slightly above the calorifier, so when the engine is shut down, the calorifier sends a reverse flow to the engine. It keeps it lukewarm overnight but leaves the water rather tepid in the morning.

Can anyone recommend a spring loaded non return valve for fitting into the pipe work from the engine? I'm thinking of something from a plumbers merchant that could be fitted to 16mm/5/8" heater hose.
see my post #7, plus, adding 50mm of insulation around the calorifier makes a big difference to the water temperature for your morning shower!

www.solocoastalsailing.co.uk
 

Oily Rag

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Many thanks for the advice. I may try to reroute the hoses, but space is limited and dexterity more so. (I was trying to keep it simple by adding just one NRV to the existing system, but you've given me food for thought. )
 

bedouin

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Well you can of course fit a non-return valve - you would want to go for a "full flow" one that will cost between £5-10 from a plumbers merchant (or Amazon). Those are spring loaded so should provide enough resistance to stop the gravity feed. You would then need hose tails or similar to connect it to your piping.
 
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