Problem getting airlock out of my cooling system

[MickH]

Hi All,

I cannot remove all the air out of my hoses going from the engine to the calorifier as the highest point of them is where they leave the engine bay and go through the bulkhead to the califorier. I havee tried running the engine several times at upto 3000revs, without success, as well as twisting and squeezing the hoses. I saw a post where bleed vents were recommended to be installed at the highest point. Would this prevent this issue whenever I change the antifreeze and if I were to cut the hose and put a "t" piece in can anyone advise what type of vent I would need and how would I attach it to the "T" piece. My hose is te standard J20 R3 16x 23mm rubber hose, and if possible a link to parts needed. Thank you in advance

[Tony Brooks]

Depending on how the hose id fitted to the calorifier you may not need a bleed valve. It might be possible to just loosen a compression/top fitting with the engine revving.

 

If you have help you could try loosening, but not removing, the hose where it returns to the engine cooling system. Get a watering can of antifreeze mixture made up and someone ready to top up the system.  Run engine at (say) 1500 to 2000 rpm and pull of the hose and at the same time put your thumb over the hose spigot in the engine side. Coolant will pour out of the hose so you may see an air bubble. The quickly remove thumb,  put hose back on and re-tighten the hose clip.

[MickH]

Hi Tony, The calorifier is under my steps which I have to unscrew and remove to get to it. The other option you mention is to remove the return hose, is this the one that goes to the engine block AND NOT the hose that goes to the thermostat housing?

[Tony Brooks]

11 minutes ago, MickH said:

Hi Tony, The calorifier is under my steps which I have to unscrew and remove to get to it. The other option you mention is to remove the return hose, is this the one that goes to the engine block AND NOT the hose that goes to the thermostat housing?

 

It will be the one that usually connects into the main cooling return to the engine water pump. The hot out engine connection is normally in the head but it might go into the body of the thermostat housing that is BELOW the thermostat  disc. A few engines like Barrus have a calorifier thermostat as well as an engine stat so without the engine make and model it is hard to advise.

 

If your return hose really does go into the block then it will have the same pressure on it as the "hot out" hose so no wonder you are having circulation problems. If the "hot out" connection is on the skin tank side of the thermostat disk (into the housing you  remove to change the stat) then again you will are likely to have circulation problems because the skin tank will, in effect, short circuit the coolant flow so it bypasses the calorifier.

 

We like photos so we can see what you are talking about. On the face of it this sounds like a bit of dodgy connecting up at present.

[Cheshire cat]

I had problems with my domestic hot water system until I used one of these. 

 

https://www.screwfix.com/p/bottle-air-vent-15mm/34359

 

The issue is a poorly designed system but the vent is a good way forward.

[MickH]

We have a Barrus Shire 12 45hp-031857,the problem really is I think because the hoses go up and over the bulkhead and then down again to the califier, with the air trapping at the top point. Thankyou ref the bottle air vent, did you do this to both hoses or just the return and please can you tell me how you attached it to the J20 R3 rubber hose as the vent has a 15mm compression joint? Thank you for your help and time, greatly appreciated

 

[Tony Brooks]

10 minutes ago, MickH said:

We have a Barrus Shire 12 45hp-031857,the problem really is I think because the hoses go up and over the bulkhead and then down again to the califier, with the air trapping at the top point. Thankyou ref the bottle air vent, did you do this to both hoses or just the return and please can you tell me how you attached it to the J20 R3 rubber hose as the vent has a 15mm compression joint? Thank you for your help and time, greatly appreciated

 

 

Will you tell us how you attach the hose to the calorifier please. You should have a barbed hose tail but what does that screw into? I  suspect that you will need to fit a T  into the calorifier outlet  so the hose tail  and a short length of pipe to connect the vent can both be fitted.  Why dies the hose need to go up and over the bulkhead? Did the builder never hear about bulkhead fittings that allow the flow to pass through the bulkhead at any level you choose and with suitable washer they maintain the water-tightness of the bulkhead.

 

In any case that trap needs to be fitted where the air gets trapped - the highest point - so putting it on the calorifier may not work. It is  still a T with suitable hose tails and a port for the trap.

 

I repeat that if the return really does go into the block you may well find the trap will do no good at all. I don't know the Barrus range of engines very well so don't know  where the return is fitted, but if Barrus/Yanmar did it I very much doubt its the block.

[MickH]

Can't speak for why the boat was built as it was, suffice to say the hoses go up through the bulkhead and down to the califorer.I cannot presently answer your enquiry about how the hose connects to the calorifier as steps are not out. The boat was built with a switchable gate valve that can heat up the radiators whilst the engine is running or if you switch it the other way to boiler the Eberspacher heats them up , whichs complicates it more I am sure.

[Tony Brooks]

28 minutes ago, MickH said:

Can't speak for why the boat was built as it was, suffice to say the hoses go up through the bulkhead and down to the califorer.I cannot presently answer your enquiry about how the hose connects to the calorifier as steps are not out. The boat was built with a switchable gate valve that can heat up the radiators whilst the engine is running or if you switch it the other way to boiler the Eberspacher heats them up , whichs complicates it more I am sure.

 

It does not really complicate it. I would seem that the builder fitted a single coil calorifier rather than a twin coil (one for engine heating and one for Eber heating) so fitted a valve to connect either to the singe coil.

 

If you don't know how the hose connects to the calorifier how do you expect us to know? Boats are not like cars that pretty much all use similar principles and components, each boat is a one off.

 

From what you say it sounds like a stupid installation almost specifically designed to trap air and make it hard to bleed so you have a choice. Keep adding components in an attempt to hide the problem while adding additional points of failure or sorting the problem out by rerouting the pipes to minimize the chances of air locks while keeping it simple.

 

[MickH]

Well thank you for your rant, most helpful

[LadyG]

14 minutes ago, MickH said:

Well thank you for your rant, most helpful

Tony Brooks knows more than anyone else about these matters, it's not a rant it's an explanation I think you should edit your post.

Perhaps you did not mean to be rude?

 

Edited May 1, 2022 by LadyG

[Tony Brooks]

2 minutes ago, LadyG said:

Tony Brooks knows more than anyone else about these matters, it's not a rant it's an explanation I think you should edit your post.

Perhaps you did not mean to be rude?

 

 

Thanks LadyG but if the OP feels it is a rant then it is his problem, not mine.  He asked a question that was impossible to answer from the info given and then from further info it seems far from competent. It must come as a nasty surprise to learn things on one's boat may not be as  they should be and that a degree of work on his part is needed. I can only advise, it sis for him to take or leave that advice. In fact I have told him waht he needs in general terms, a T fitting, hose tails etc but suspect he does not have a clue what I am talking about.

[Tracy D'arth]

10 minutes ago, Tony Brooks said:

In fact I have told him what he needs in general terms, a T fitting, hose tails etc but suspect he does not have a clue what I am talking about.

Not an excuse for sarcasm though.

34 minutes ago, MickH said:

Well thank you for your rant, most helpful

If you want advice a polite question and answer session is the best way. But you need to understand that your boat will be totally different from anyone elses.

[MickH]

Not sure why you accuse me of sarcasm, you clearly know it all, I know very little but willing to learn, but never needed to be told that every boat is different, nor do I need to read that "I would not have a clue". I will leave you to roost a totally unhelpful forum, but at least I can spell, perhaps you too could learn something, before sending your highly unhelpful comments, read them first or at least learn how to check a spell checker!!!

To Tracy D'arth, a polite question and answer works both ways, I came on for geniune help but received a persons personal assumptions and accusations

[ditchcrawler]

4 hours ago, MickH said:

Hi All,

I cannot remove all the air out of my hoses going from the engine to the calorifier as the highest point of them is where they leave the engine bay and go through the bulkhead to the califorier. I havee tried running the engine several times at upto 3000revs, without success, as well as twisting and squeezing the hoses. I saw a post where bleed vents were recommended to be installed at the highest point. Would this prevent this issue whenever I change the antifreeze and if I were to cut the hose and put a "t" piece in can anyone advise what type of vent I would need and how would I attach it to the "T" piece. My hose is te standard J20 R3 16x 23mm rubber hose, and if possible a link to parts needed. Thank you in advance

I have a vent at the highest point about 3 foot above the top or the engine after the pipes have gone through the bulkhead round behind the bath, across the back wall and up in the calorifier cupboard.
What I do is fill the system, run the engine until warm and then open the vent, By  running the engine the coolant has expanded and pressurised so pushes the air out of the vent. It only requires doing after draining the system. 

Its not an auto vent but 

[Tracy D'arth]

25 minutes ago, MickH said:

Not sure why you accuse me of sarcasm, you clearly know it all, I know very little but willing to learn, but never needed to be told that every boat is different, nor do I need to read that "I would not have a clue". I will leave you to roost a totally unhelpful forum, but at least I can spell, perhaps you too could learn something, before sending your highly unhelpful comments, read them first or at least learn how to check a spell checker!!!

To Tracy D'arth, a polite question and answer works both ways, I came on for geniune help but received a persons personal assumptions and accusations

Bye.

[Peugeot 106]

Mick I think you are being a bit touchy. If you look at Tony’s profile you will see exactly how many people he has helped in the past. Maybe if you post a picture as he has requested he will solve your problem too.(assuming you are both still speaking) Tony is not perfect but he knows more than most and is very good at holding hands from a distance. Also he doesn’t tend to abandon you. Over to you but I find watching this problem solving interesting and instructive. 

[Cheshire cat]

Ditch crawlers solution looks like a good alternative but either way you will need to cut a hose, put a tee piece in and attach a vent. Really simple to do and less than  a tenner. Good luck

[Tony Brooks]

30 minutes ago, ditchcrawler said:

I have a vent at the highest point about 3 foot above the top or the engine after the pipes have gone through the bulkhead round behind the bath, across the back wall and up in the calorifier cupboard.
What I do is fill the system, run the engine until warm and then open the vent, By  running the engine the coolant has expanded and pressurised so pushes the air out of the vent. It only requires doing after draining the system. 

Its not an auto vent but 

 

Those would be far less likely to leak than the automatic types, especially if it is to be mounted where dismantling steps is required to access.

[ditchcrawler]

2 minutes ago, Tony Brooks said:

 

Those would be far less likely to leak than the automatic types, especially if it is to be mounted where dismantling steps is required to access.

We had the automatic ones in the accommodation offshore, A very impressive fountain when they fail

[MtB]

12 hours ago, MickH said:

Not sure why you accuse me of sarcasm, you clearly know it all, I know very little but willing to learn, but never needed to be told that every boat is different, nor do I need to read that "I would not have a clue". I will leave you to roost a totally unhelpful forum, but at least I can spell, perhaps you too could learn something, before sending your highly unhelpful comments, read them first or at least learn how to check a spell checker!!!

To Tracy D'arth, a polite question and answer works both ways, I came on for geniune help but received a persons personal assumptions and accusations

 

 

Tony has decades of experience and a long history on here of helping people with detailed and relevant advice, but to do this he needs (as we all do) co-operation from the needer-of-the-advice by answering the questions asked.. Instead of ignoring the questions and getting arsey when pressed for the information needed.

 

We get this more often on here, people expecting us to know what is installed in their boats without them telling us, or providing photos.

 

 

[Slow and Steady]

I'm with Tony - instead of treating the symptom with a valve to let the air out, tackle the cause and reroute the pipes with bulkhead connectors so you never have to think about it again. Not much more effort for this permanent cure and in the future you won't have to remove your steps every time there is an air lock.

 

Boat outfitters and subsequent equipment installers can be bliddy lazy to save themselves a few minutes or a few pennies, storing up trouble that takes hours to sort out where a minutes would avoided the problem. Do they care? No, they are trying to maximise their profits and each cut corner adds up to both that and future owner's misery. Quite amusing how many decades old boats still carry these initial faults along with bodges to overcome them instead of correcting the original faults.

Edited May 2, 2022 by Slow and Steady

[MtB]

41 minutes ago, Slow and Steady said:

Boat outfitters and subsequent equipment installers can be bliddy lazy to save themselves a few minutes or a few pennies, storing up trouble that takes hours to sort out where a minutes would avoided the problem. Do they care? No, they are trying to maximise their profits and each cut corner adds up to both that and future owner's misery. Quite amusing how many decades old boats still carry these initial faults along with bodges to overcome them instead of correcting the original faults.

 

 

And in a single paragraph you have encapsulated the difference between a bargain basement boat (e.g. a Liverpool boat) and a good quality build, say the older Aqualines. There are thousands of things in the build of a NB that can be done well, or a little bit quicker and a little bit cheaper. When all the chances to cut corners and save money on the build, the final selling price will be £ks cheaper making a new boat 'affordable' when otherwise it might not be.

[Slim]

I've been following this topic and have been waiting for photos or a clear explanation of the pipe runs. Now it looks as if the topic has stalled. Perhaps from a meeting of exasperation on one side and frustration on the other. I doubt that the problem itself is a difficult one to resolve. 

[MickH]

Thankyou all for your constructive comments, I don't want to fall out with anybody, but honestly I do not need to be told that it is a dodegy job that has been done, or that I do not have a clue!!! I may be a bit touchy yes and that is why, I am happy to accept constructive criticism. It is only too common in most marina's today let alone at building stage. I have had t oput many bodges right and wish to do so correctly and so I do not have to go back and do the same job twice. Even on this post there are two suggestions one being putting a tee in along with a vent, preferably a manual one or reroute the hoses through the bulk head, which probably would be more preferable. for the latter.I have looked on midland chandlers and cannot see a suitable bulkhead connector, my hoses are J20 R3 16mm x 23mm