Ray Posted March 30, 2022 Share Posted March 30, 2022 I'm trying to find/release a suspected air lock (Engine runs cool, very little hot water at tap, thermostat changed) On top of the Calorifier is a red valve, when pressed water runs freely into bilge but I cant see where from. What am I doing? Will it help? Should I stop? 1 Quote Link to comment Share on other sites More sharing options...
Smoggy Posted March 30, 2022 Share Posted March 30, 2022 That will be the pressure release valve and the water comes from inside the calorifier and will be domestic waater not coolant, it's likely the coolant side needs bleeding if an air lock. If you undo the highest section of coolant hose and attach a length of clear hose you could suck on it and see the coolant before getting a gob full to get any air out. 1 Quote Link to comment Share on other sites More sharing options...
BrundallNavy Posted March 30, 2022 Share Posted March 30, 2022 I connected a hose pipe to mine to give it a pressurised feed once it was running correctly I drained the header tank and refilled with neat coolant. The engine would not give sufficient flow to blow the air lock through. 1 Quote Link to comment Share on other sites More sharing options...
grendel Posted March 30, 2022 Share Posted March 30, 2022 1 hour ago, Ray said: On top of the Calorifier is a red valve, when pressed water runs freely into bilge but I cant see where from. its the comic relief valve, you press it water spurts out from where you dont know, everyone laughs- comic relief valve. simples 2 Quote Link to comment Share on other sites More sharing options...
annv Posted March 30, 2022 Share Posted March 30, 2022 Hi Ray Remove the header tank cap then undo the top hose of the two that come from the engine with engine running at a fast tick over gently full top hose of off the calorifer coolest from the engine should run out if only air hold until coolant runs out then push hose back on and refasten, header tank my want topping up with a 50/50 mixture of antifreeze aftr wards, then as engine gets hot so should the hose at the calorifera, if no flow engine will need flushing or hose may have collapsed internally,or coil in calorifira may be blocked, have you checked the temp of hose from engine as i last suggested to you?. the water will only get as hot as the engine provided the engine coolant is able too flow through coil in the calofirera and back to engine at its worse the engine coolant pump may be worn on the vans and need replacing if no flow. John 1 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 30, 2022 Author Share Posted March 30, 2022 Hi John, I'll admit I'm struggling to identify what goes where! The two hoses to/from the calorifier disappear toward the calorifier but I can't get near enough to it to see which is which, certainly can't reach the hose connectors at that end. It is mounted horizontally in a space I am not built to enter 🙄 At the engine end of the hoses they run next to each other on a bulkhead, both became hot to touch as far as I could reach but that wasn't far. I fear that I may have to be calling the boat yard again to be on the safe side. Quote Link to comment Share on other sites More sharing options...
annv Posted March 31, 2022 Share Posted March 31, 2022 Hi Ray a picture might help, but if you cant reach the 1/2 inch hoses that come from the engine you will have may be remove every thing flush through with hose and start again the calorifier will have 4 hose connections 2 to engine coolant and a inlet from pump and outlet to taps, the red capped valve at the top is a pressure release valve which may have a hose connected to it to drain/divert any water that gets released by the valve over board or bilge. John Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 Thank you so much for your patience John... A photo it is! Where I have marked 1 goes to the higher connection on the calorifier, no. 2 to the lower. With the engine cold and running at idle both warmed up at the same rate. With the engine still running I pulled hose 1 off, coolant came out straight away, I replaced it and did the same with hose 2 with the same result. Now in an attempt to understand the system better I have been reading up similar situations online and I wonder if it's possible that these two hoses are connected wrong? I understand this is not uncommon. When I removed hose 1 the coolant flowed from the hose, when I removed hose 2 the coolant flowed from the engine... this was the opposite to what I expected. Although I cant access the calorifier the hoses at the engine are easily accessible. Is there any point in me switching these hoses to see if I'm right? Quote Link to comment Share on other sites More sharing options...
Smoggy Posted March 31, 2022 Share Posted March 31, 2022 Has it always had this problem and has the plumbing been changed? 1 Quote Link to comment Share on other sites More sharing options...
grendel Posted March 31, 2022 Share Posted March 31, 2022 just a thought, is the connection on the calorifier higher or lower than the engine connection, as any air will be trapped at the highest point in the system, so that would be where you would need to bleed the air from. 1 Quote Link to comment Share on other sites More sharing options...
annv Posted March 31, 2022 Share Posted March 31, 2022 Hi Ray Normally the hose to the top of calorifier comes from the rear of cylinder head as Smoggy says has it been like this before and did you have hot water. The engine looks new. you will get water from both as they are below level of header tank, both hoses getting warm equally is not right, is there a connection blanked off at rear of cylinder head. do you have a user hand book for the engine? what engine is it! can you feel the hoses closer to the calorifiera e the top one should get warmer first if you take both hoses of can you see the impellor of the pump in one of them the return hose from the calorifier should go there ie return from tank. if you would like to phone me while at boat seed me a email and i will phone you. A picture from directly above hose connections would help John 1 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 Thank you guys! We have never had enough hot water since we bought the boat, it is only recently that I noticed the temp guage showing her running cool(ish) but that is quite possibly how it has always been. The engine is a Nanni 4220 HE, as far as I know it is the boats original - 1985 Broom 29 The calorifier is horizontal but as near as the eye can tell the higher hose is level with the engine, photo attached where you can see the hoses running parallel and level. In my first photo the return hose is the one marked 2, it goes into the base of the housing you can see where the brass is showing, as far as I know this houses the impeller ?? Am home now but can get more photos tomorrow pm, I haven't got a user manual though I'm afraid. Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 Edit - Boat is '95 not '85, apologies. Quote Link to comment Share on other sites More sharing options...
Smoggy Posted March 31, 2022 Share Posted March 31, 2022 On the domestic water side check the water from pump goes in at the bottom and the water to taps comes out from the top, mine was wrong way round when we got it and only got warm, swapped over and now gets hot within 20 mins at River speeds, my engines run cool at river speeds for ages. 1 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 I'll check that first as soon as I go back, thank you 👍 Quote Link to comment Share on other sites More sharing options...
dnks34 Posted March 31, 2022 Share Posted March 31, 2022 I don't think theres an impeller in the brass coloured housing. I thought the closed circuit water pump was on the front of the engine under a cover like a car? I may be mistaken. The nut on the top of the brass housing is what I used to bleed our Nanni 50hp when I had worked on the cooling circuit. The only thing that gave us trouble with hot water with ours was a dodgy Thermostatic Mixer Valve but that wouldn’t affect engine temp. 1 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 6 minutes ago, dnks34 said: I don't think theres an impeller in the brass coloured housing. I thought the closed circuit water pump was on the front of the engine under a cover like a car? I may be mistaken. The nut on the top of the brass housing is what I used to bleed our Nanni 50hp when I had worked on the cooling circuit. The only thing that gave us trouble with hot water with ours was a dodgy Thermostatic Mixer Valve but that wouldn’t affect engine temp. That makes sense... I did loosen it with the engine on tick over but no water came out. Do you have to take it right off? Maybe it's something I need to look at again. Quote Link to comment Share on other sites More sharing options...
BrundallNavy Posted March 31, 2022 Share Posted March 31, 2022 We have a Nanni N65 and our water does not get particularly hot we tend to pop the immersion on when the engine is running for around 20 mins Our engine runs around 70 degrees. 1 Quote Link to comment Share on other sites More sharing options...
dnks34 Posted March 31, 2022 Share Posted March 31, 2022 If memory serves it was just a case of undoing it a few turns till water started coming up the threads. 1 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 9 minutes ago, BrundallNavy said: We have a Nanni N65 and our water does not get particularly hot we tend to pop the immersion on when the engine is running for around 20 mins Our engine runs around 70 degrees. That's really helpful to know, thank you. Our engine gets to about 75 degrees on a run, so engine temp may not be the problem I thought! We do however only get enough warm water at the tap (not hot, just warm) for both of us to wash our hands even after cruising. We have no immersion heater! Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 14 minutes ago, dnks34 said: If memory serves it was just a case of undoing it a few turns till water started coming up the threads. In that case I have to go back to do that again, I loosened it but there was no water! Quote Link to comment Share on other sites More sharing options...
annv Posted March 31, 2022 Share Posted March 31, 2022 Hi Ray Looking at your tank is it held by two straps or does it have a fixed base? what i am thinking is the tank needs rotating 90*, your engine is a base Kubota Nanni is a French firm that Marinizes them, on my Kubota the heater pipe comes from the rear of cylinder head. suggest a trip to Peachments at Brundle they are the local agents. i have tried to google the cooling system but unable to access a picture, except for one that shows there are two outlets on top of head near thermostat housing. the engine should run with a 85 degree thermostat does your engine get to this temp? John 1 Quote Link to comment Share on other sites More sharing options...
dnks34 Posted March 31, 2022 Share Posted March 31, 2022 4 minutes ago, Ray said: In that case I have to go back to do that again, I loosened it but there was no water! did you do it whilst the engine was running and hot? If you undo it slowly water ought to be forced out under pressure. 1 Quote Link to comment Share on other sites More sharing options...
Ray Posted March 31, 2022 Author Share Posted March 31, 2022 6 minutes ago, annv said: Hi Ray Looking at your tank is it held by two straps or does it have a fixed base? what i am thinking is the tank needs rotating 90*, your engine is a base Kubota Nanni is a French firm that Marinizes them, on my Kubota the heater pipe comes from the rear of cylinder head. suggest a trip to Peachments at Brundle they are the local agents. i have tried to google the cooling system but unable to access a picture, except for one that shows there are two outlets on top of head near thermostat housing. the engine should run with a 85 degree thermostat does your engine get to this temp? John The position/fixing is something I'll have to go back and check John. We got to 75 on a recent run of about an hour. This was a simple gentle cruise mostly about 1100 revs. I would imagine but can't say for sure that if we were punching the tide at Yarmouth for example we would go a bit higher. Quote Link to comment Share on other sites More sharing options...
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