Help Calorifier Problems M135 Perkins

[undercutter]

For some time now our clarifier system for the Fresh hot water from the engine cooling circuit has not functioned.

The unit is installed a sole eight with the inlets to the heat exchanger 2" above the sole level. The rad cap on the coolant tank is 4" below the sole level.

There is no overflow reservoir in the system.

The engine heat exchanger is new.

All the hoses as well as the Thermostat housing were replaced.

Coolant tank is new as well as rad cap,etc.

The operating engine temperature is 80C.

The engine never moves from this temperature after warming up no matter how hard I push the engine. I ran her at 2400 RPM for more than an hour heading to Southport and the needle never flickered.

Have flushed and tested the coolant lines from the engine to the hot water tank.
Pushed water both ways through both hoses as well as the heat exchanger in the water tank so there a no check valves in the system.

Ensured Orifice for flow control on engine heating circuit feeding the calorifier system was clear with a small precision screwdriver well into the pipe.

Today started the engine at the dock ran to warm up 80C at high idle to ensure thermostat is open.

Bled the coolant lines at the heat exchanger to ensure no air at this point as it is higher than the rad cap. Good pressure, and obviously fluid but impossible to tell if there was any flow.

Hoses were cool to the touch. Hoses in Engine compartment were warm and obviously hotter the closer to the engine. As soon as the hoses clear the engine compartment there is no obvious heating effect and would indicate no flow.

Transmission in forward to load the engine ran up to 1600 RPM for 15 minutes. All conditions the same and I bled the hoses again at the water tank use to make sure. Continued to run the engine for another 15 minutes under load and no obvious visual changes.

It seems that the obvious cause would be no flow whether to a airlock or possibly a bad cooling system pump on the engine. However their is no obvious signs of a water pump failure such as overheating.

I do have a brand new coolant water pump in spares but I am loathe to install it if there is nothing wrong with the old one.

Previous repairs including replacing the oil cooler in the water jacket due to gasket failure. Apparently you have to been extremely careful when changing fuel filters as any leaked fuel will eat these old gaskets. Obviously a problem as they have upgraded the gaskets to metal with an embedded o ring. I believe that the problem started sometime around this repair that was done at the same time as a new injection put was installed.

I read one thread somewhere that said that a separate coolant tank mounted higher than the highest point of the hot water tank was required when mounting the hot water tank higher than the engine. The factory rad cap was then installed on this new tank and a higher rated cap was installed on the original coolant tank. Unfortunately this does not explain why the system worked for the first 5 years we owned the boat.

Thanks for the help.

[undercutter]

Just to put this back on top for the NA's waking up. I could use some input here.

[undercutter]

Keep bumping this up to the top hoping that someone can provide some information here.

[undercutter]

So I thought I would have another go at the calorifier system for the hot water tank. I attached a pdf file with a good picture of the cooling side of the engine.

The 5/8" hoses for the system replace the small line from the top of the pump to a fitting on the piping as shown in the picture in the attachment.

Objective for today was to determine whether an airlock was stopping the circulation of the coolant through the heat exchanger in the water tank.

Added a tee to one of the lines at the water heater and ran a hose 30 inches higher than the fittings on the water tank and above the entire water tank by 18" or more. Installed a threaded fitting which was capable at the end of the hose.
After ensuring that coolant tank was full, started the engine. With engine running added coolant into my jury rigged reservoir or header hose until coolant was within 1" of top of hose at least 18" higher than water tank.

Once engine was warm I increased RPM up to 1500. On observing the header hose the coolant had dropped to the level of the T connector in the supply hose to the hot water tank. This would indicate that the water pump is working. I then refilled the header hose back up to the previous level with the hose straight up and capped it.

Ran the engine for 15 minutes under load at 1600 RPM. Checked the hoses at the hot water tank and they were not even warm. No obvious air in the system. With the engine revved at 1600 RPM I could remove the car off the header hose completely and the coolant stayed at a consistent level. If I lowered the engine RPM the coolant level would rise and sell over the top. Recapped the hose and let the engine cool down.

Conclusion(s) An air lock in the system is not the cause of the problem and the water pump seems to be at least pulling coolant out of the calorifier system when the engine is revved up.

So next I wanted to see if there was any flow at all through the hoses feeding the hot water heater. I bypassed the hotter tank completely with a clear loop of hose leaving the tee and my header hose in place to prime the system. Again filled the system at idle this time and then followed the same procedure adding coolant once the engine was revved up to make sure no air could possible be in the system. If I raised the bypass loop up higher than the tank I could get a few residual bubbles (very small) to form at the top of the loop. These bubbles had no movement in any direction indicating no flow.

Conclusion(s) WTF

Obviously I must be making some unwarranted assumptions or reaching false conclusions based on my experiments.

Any help or ideas at all would be appreciated.

[wiekeith]

Originally Posted by undercutter

So I thought I would have another go at the calorifier system for the hot water tank. I attached a pdf file with a good picture of the cooling side of the engine..

I might be missing something, but I don't see the cooling system on the pdf.

[captjcook]

A simple guess...

Your loop is not connected in the path of flow. Both calorifier connections are on the same side, whether pressure or return, resulting in no flow.

Edit: In your case, my guess is that both hoses are connected on the return side or it would have flowed out hose with cap.

Work was done on engine...something was changed. If the pump was bad it would overheat.

Since the calorifier is above the fill cap, a header tank is indicated...(lest gravity drain the system with cap removed) lacking one is not why it doesn't work.





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[Steven UK]

But he said it did work then stopped... I'm not too familiar with these units but you could try joining the two hoses that go to the water tank and see if water flows, if not try putting the hose loop lower than the the hot water tank. You are checking for blockage in the tank and airlock. I would suspect the latter.

Good luck.

[wrwakefield]

Hi Undercutter,

How frustrating this must be- especially in the cooler weather months...

I have a similar set-up, but with an overflow tank from the engine coolant system mounted at the same height as the hoses to/from the water heater. It works very well. I don't know if the coolant tank contributes to that success. [It was in place before the new water heater was installed above the engine...]

Since yours did work, and stopped, another possible contributing factor may be the hoses. Some hoses can delaminate causing the inner layer to collapse during suction, effectively closing flow through the hose. Since it is the inner hose collapsing, it is not visually evident on the outer hose... [I have experienced this anomaly with fuel hoses first hand in the past...]

To test this premise, I might try a length of new heater hose [for your spares...] connected to the engine where the water heater hoses connect. Leave this new hose in a loop and see if it gets hot. Raise it to the height of your water heater and see if it stays hot... Simple test, and you can use this hose to replace your old ones should this test determine they are bad.

Regarding air locks, I believe the efforts you describe demonstrate that is likely not the issue.

For future consideration regarding automatically purging air from the hydronic loop, here is an excerpt from one of my posts describing how we deal with air bleeding hydronic heating loops [e.g., water heater, hydronic heater cores, etc.]

3) Bleeding air from hydronic loops can be quite a chore as the top of each loop is not always conveniently accessible. [I know ours aren't...]

To make this easy, we use small, float style [vs. Schrader valve; e.g., Watts brand] automatic air bleeders used in home boiler heating systems. [Cheap at ~US$10-15/each]

Typically we install a T at the top of each hydronic core and install a ball valve [to isolate the bleeder when not needed, and for maintenance...] then the the air bleeder in the highest port of the T. [i.e., Where the coolant return line to the engine exits the core.]

Basically, air bleeders need to be installed at a high point in each coolant loop.

We installed air bleeders on our water and bus heaters. They eliminate manual bleeding- even when first commissioning a hydronic system...

Hopefully the heat exchanger in your water heater isn't the culprit, and the above new hose loop test will help determine that.

Best wishes resolving this issue, and hot showers for all!

Cheers! Bill

[undercutter]

Originally Posted by wiekeith

I might be missing something, but I don't see the cooling system on the pdf.

Just a picture of the cooling side of the engine but if you blow it up you can see the individual components very well.

The ports for the calorifier system in this picture are connected together by a short hose going to the top of the pump from the piping going to the heat exchanger port. i.e. there is no clarifier system installed in the pic.

I assumed that the pressure side was the fitting on the piping and the return went directly to the top of the pump. The hole in the port in the piping is reduced to control flow. This orifice is clear as I used a precision screwdriver long enough to protrude into the centre of the pipe to check.

[captjcook]

Page 63

https://www.maritimepropulsion.com/files/pdf/1001294






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[undercutter]

Originally Posted by Steven UK

But he said it did work then stopped... I'm not too familiar with these units but you could try joining the two hoses that go to the water tank and see if water flows, if not try putting the hose loop lower than the the hot water tank. You are checking for blockage in the tank and airlock. I would suspect the latter.

Good luck.

From my 4th, post "So next I wanted to see if there was any flow at all through the hoses feeding the hot water heater. I bypassed the hotter tank completely with a clear loop of hose leaving the tee and my header hose in place to prime the system. Again filled the system at idle this time and then followed the same procedure adding coolant once the engine was revved up to make sure no air could possibly be in the system. If I raised the bypass loop up higher than the tank I could get a few residual bubbles (very small) to form at the top of the loop. These bubbles had no movement in any direction indicating no flow."

So this is not the answer however please keep thinking about it. Any suggestions are appreciated.

[undercutter]

Originally Posted by captjcook

Page 63

https://www.maritimepropulsion.com/files/pdf/1001294

Attachment 135754




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Well there you go. Obviously these connections are not as on my engine.

The question is now why did the damn thing work for so long and then just quit even though it was plumbed differently??? Guess it doesn't really matter as long as this solves the problem.

Thank you very much.

[captjcook]

My pleasure...

Not always the things we don't know...sometimes it's the things we think we know for sure, that are wrong...something my Dad used to say...


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[undercutter]

Originally Posted by captjcook

My pleasure...

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It is even worse than that as I had the document you sent having downloaded it 2 days ago on my new computer. (My computer crashed and my flash drives are back in Canada with backups to all the manuals)

So it seems that the original installation was incorrect!!! Another clue was the 5/8" hose on the system and the output port for the system being 3/4". I had actually already put an adaptor at that location already as I do not know how the installer managed to get the hose on in the first place. On closer examination it is apparent that this flange fitting was not original. All this doesn't explain how the system ever worked in the first place but theoretically I don'y know why it wouldn't work now.

The original flow for that orifice port should just loop back to the top of the pump and is not intended for this purpose although this is also the return for the calorifier as well. Would be nice to know what the purpose would be other than to relieve an airlock as does it otherwise makes sense to recirculate the coolant??? Lot's of questions that will leave me scratching my head and causing worry that something else is wrong if it all works fine when plumbed properly.



So now it is back to England for the flange fitting with the additional port. I should be able to get it here in Southport or have it made but I am sure that the supplier would only end up ordering from England anyway and for 5 times the price. I will also have to get the hose and spare to revert that portion back to original. Won't be able to finish it for at least a week so I guess I get to put it all back together and tear the boat apart again. The joy. lol

The wife get's back next Thursday so that will put an end to the projects. Planning on replacing the engine mounts and aligning the engine on Tuesday if the parts get here on time.

The price in Australia was $485.00 for the rear mounts and $280.00 for the front mounts. Total of $1,530.00 AU. I paid 297.00 GBP including shipping from England for all four. You mates are getting soaked bad here in Oz or maybe I just need some good suppliers.

[captjcook]

I thought long and hard...how to respond...

First, I can relate to your frustration. I see stuff like this, way to often. Learned not to get hung up on why.

I have learned to just be happy when I get it working! Then go sailing!

Fair winds and HOT showers!


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