Author Topic: Water not circulating around calorifier  (Read 162 times)

StuartAdair

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Water not circulating around calorifier
« on: August 22, 2022, 07:06:20 PM »
Hi folks,
Got a ListerPetter LPW4 fitted in a Norfolk Broads boat. Ran her up river yesterday and the hot water was cold. I've had a check of the system today and its all a bit strange. Referring to the attached diagram I pulled off pipe 1 with the engine running and a tiny trickle of water came out (Flow to the heater). Same for pipe 2 (Return from the heater). The engine isn't over heating, runs fine and when warmed up you can feel heat in the places I've marked as hot.

Any ideas why the water isn't moving around the heater ?

Thanks
Stu

Diesel Engineering

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Re: Water not circulating around calorifier
« Reply #1 on: August 23, 2022, 02:52:17 AM »
Possibly you have an air lock in your calorifier. This is normally the problem and sometimes can be quite difficult to get all the air out. Another possibility is an incorrect thermostat fitted. Your thermostat should have a flat plate on the lower side. This is to shut the internal bypass off as the engine warms up. The early engines just used a standard type thermostat but as your engine is a later model it should have the thermostat as described.,

StuartAdair

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Re: Water not circulating around calorifier
« Reply #2 on: August 23, 2022, 05:53:32 AM »
Thanks for your reply. I'm going to take the thermostat out and do some investigating...