Header tank coolant level

[Bones]

There are a few vague bits in this that - as a bear of very little brain - I would like to clarify.

 

When you say the hot water doesn't get hot, do you mean the water in the engine, in a calorifier or in a heating system?

 

What has changed that could have allowed air into one of these systems?

 

Which header tank are you talking about - the one on the engine or one on a heating system?

 

 

Richard

 

You can leave the cauliflower on the side of your plate, just eat your peas...

 

 

There is no problem with the engine. The water in the cauliflower doesn't get hot hot. I dont think the system was set up properly, so it is a bit random. I have found that filling the header tank (the one high up above the cauliflower) then waiting for it to gurgle down, and keeping doing that for a while. Then waiting, and then starting the engine the water heats up beautifully after a while. The thing is, the overflow of the coolant is quite a lot too, which I don't think is good. If I don't repeat the gurgling proceedure every time I start the engine, then the water in the cauliflower doesn't get hot......

 

The pipes are connected properly.

Edited October 13, 2008 by Bones

[RLWP]

There is no problem with the engine. The water in the cauliflower doesn't get hot hot. I dont think the system was set up properly, so it is a bit random. I have found that filling the header tank (the one high up above the cauliflower) then waiting for it to gurgle down, and keeping doing that for a while. Then waiting, and then starting the engine the water heats up beautifully after a while. The thing is, the overflow of the coolant is quite a lot too, which I don't think is good. If I don't repeat the gurgling proceedure every time I start the engine, then the water in the cauliflower doesn't get hot......

 

The pipes are connected properly.

 

Right,

 

The cauliflower is a big tank of water - sometimes hot - that is pressurised by your water pump. The header tank has nothing to do with that part.

 

Through the cauliflower runs one or two coils of pipe. One of these is fed with hot water from your engine. The engine has a header tank, and pouring in water to eliminate the gurgles would make the cauliflower work. BUT. This means you are losing water from the engine. This is a BAD THING. This header tank will have a metal cap with a springy thing on the bottom.

 

If there is a second coil, this is for hot water from your boiler system. This too will have a header tank and is usually unpressurised. Pouring water into this to eliminate gurgles will also make the cauliflower work. BUT. This means you have a leak in your boiler circuit, and this is a BAD THING.

 

Which header tank are you pouring water into? What sort of cap has it got?

 

Richard

Edited October 13, 2008 by RLWP

[Bones]

Right,

 

The cauliflower is a big tank of water - sometimes hot - that is pressurised by your water pump. The header tank has nothing to do with that part.

 

Through the cauliflower runs one or two coils of pipe. One of these is fed with hot water from your engine. The engine has a header tank, and pouring in water to eliminate the gurgles would make the cauliflower work. BUT. This means you are losing water from the engine. This is a BAD THING. This header tank will have a metal cap with a springy thing on the bottom.

 

If there is a second coil, this is for hot water from your boiler system. This too will have a header tank and is usually unpressurised. Pouring water into this to eliminate gurgles will also make the cauliflower work. BUT. This means you have a leak in your boiler circuit, and this is a BAD THING.

 

Which header tank are you pouring water into? What sort of cap has it got?

 

Richard

 

I only have one coil. The coolant in the engine has a non pressurised cap. The one positioned above the cauliflower (connected to the engine coolant) has a metal cap with a springy thing on the bottom.

 

I have a dry bilge....

 

 

edit to say - by non pressurised cap I mean the one on the engine itself doesn't have a springy whatsit.

Edited October 13, 2008 by Bones

[RLWP]

I only have one coil. The coolant in the engine has a non pressurised cap. The one positioned above the cauliflower (connected to the engine coolant) has a metal cap with a springy thing on the bottom.

 

I have a dry bilge....

 

 

edit to say - by non pressurised cap I mean the one on the engine itself doesn't have a springy whatsit.

 

So, my spidey senses tell me that if you poured water into the header tank with the pressurised cap, it would come out of the cap on the engine. You have a remote header tank on your engine. Fair enough, my 1972 midget has one too.

 

What kind of cooling tank have you got? I guess a skin tank on the side of the swim.

 

Richard

 

Don't worry, there will be some advice coming soon...

[Bones]

So, my spidey senses tell me that if you poured water into the header tank with the pressurised cap, it would come out of the cap on the engine. You have a remote header tank on your engine. Fair enough, my 1972 midget has one too.

 

What kind of cooling tank have you got? I guess a skin tank on the side of the swim.

 

Richard

 

Don't worry, there will be some advice coming soon...

 

 

It is Keel Cooled.

 

I have a dry bilge.

[John Orentas]

In the real world the air does not always work it's way to the top of a system, in fact I did an experiment once which showed that a pipe needed to be one inch or more diameter to be sure that air will gurgle up through it.. You may not be talking about 'bubbles' here it is possible you have a cauliflower half full of air.

 

For a start you can go around the entire cooling system, starting with the highest undo the coolant connections making sure that any air comes out and stays out while you connect up again, it is sometimes an idea to install a few permanent bleed points.. Not a perfect science though it may take a lot of fiddling about.

[Bones]

In the real world the air does not always work it's way to the top of a system, in fact I did an experiment once which showed that a pipe needed to be one inch or more diameter to be sure that air will gurgle up through it.. You may not be talking about 'bubbles' here it is possible you have a cauliflower half full of air.

 

For a start you can go around the entire cooling system, starting with the highest undo the coolant connections making sure that any air comes out and stays out while you connect up again, it is sometimes an idea to install a few permanent bleed points.. Not a perfect science though it may take a lot of fiddling about.

 

 

OH dear.... half air in my cauliflower? How on earth do I determine whether that is true? Do I twist the pressure release/relief valve on the top of it and see if I get wet (when the water is cold)? I am pretty sure I did last time I tried that to see what it did.

 

Sooooo, I just undo the pipe and wait for the air to come out - do I have the engine running for this? Or do I just do it.

[RLWP]

It is Keel Cooled.

 

I have a dry bilge.

 

The thing is, the overflow of the coolant is quite a lot too, which I don't think is good

 

OK, I'm with John on this. We concur with you, you have air in your system. Try Rennies. But for your engine:

 

Top up your highest header tank until it overflows (you should really be using an anti-freeze mix). Start undoing joints in the engine cooling pipes and see what comes out - it should be water/anti-freeze. Do the joint up again when only wet stuff comes out.

 

The air will hide in high up places and in remote parts of the system. Seek it out. Calorifier coils are popular hiding places.

 

Don't forget that if you take a pipe off, stuff will come out of the pipe and the thing it was pushed on to.

 

Do this with the engine off and the coolant cold. It's a bad enough job as it is.

 

Richard

 

You won't have a dry bilge when you have finished this...

 

OH dear.... half air in my cauliflower? How on earth do I determine whether that is true? Do I twist the pressure release/relief valve on the top of it and see if I get wet (when the water is cold)? I am pretty sure I did last time I tried that to see what it did.

 

Sooooo, I just undo the pipe and wait for the air to come out - do I have the engine running for this? Or do I just do it.

 

That pressure relief valve is for the water inside the cauliflower, not the water in the coil. Leave it alone, there's going to be enough mess as it is.

[Bones]

OK, I'm with John on this. We concur with you, you have air in your system. Try Rennies. But for your engine:

 

Top up your highest header tank until it overflows (you should really be using an anti-freeze mix). Start undoing joints in the engine cooling pipes and see what comes out - it should be water/anti-freeze. Do the joint up again when only wet stuff comes out.

 

The air will hide in high up places and in remote parts of the system. Seek it out. Calorifier coils are popular hiding places.

 

Don't forget that if you take a pipe off, stuff will come out of the pipe and the thing it was pushed on to.

 

Do this with the engine off and the coolant cold. It's a bad enough job as it is.

 

Richard

 

You won't have a dry bilge when you have finished this...

 

 

 

That pressure relief valve is for the water inside the cauliflower, not the water in the coil. Leave it alone, there's going to be enough mess as it is.

 

And do I do this all the way down to the keel cooler bits?

[LEO]

Hi,

 

Have been following this one, are you sure that the flow of water through the calorifer is correct? the water has to be 'pushed' through the internal coil from the bottom to the top (ie, on a BMC 1.5 the pipe from the rear of the cylinder block connects to the lower part of the coil, returning from the top to a point on the block near the engine water pump).

 

I reversed them on mine and the water was cool, reconnected them as above and it returned to working at normal temperature.

 

Engine was a 1.5 BMC raw water cooled with a heat exchanger.

 

Hope that helps.

 

Albion

[Bones]

Hi,

 

Have been following this one, are you sure that the flow of water through the calorifer is correct? the water has to be 'pushed' through the internal coil from the bottom to the top (ie, on a BMC 1.5 the pipe from the rear of the cylinder block connects to the lower part of the coil, returning from the top to a point on the block near the engine water pump).

 

I reversed them on mine and the water was cool, reconnected them as above and it returned to working at normal temperature.

 

Engine was a 1.5 BMC raw water cooled with a heat exchanger.

 

Hope that helps.

 

Albion

Hi,

Yes I am sure mine are the correct way around.

[RLWP]

And do I do this all the way down to the keel cooler bits?

 

I would.

 

This isn't an exact science. You have an engine for a car or lorry shoved in a boat with a made up cooling system and a tank of water shoved on the side. No-one sat down and designed this with a view to making it easy to maintain. As long as they could get the bits that were about right at the right price and they all fitted in the space, that is as far as it went. If it were a car then there would be a department to work on servicing and they would write a manual and maybe get the design changed. Here - it's you.

 

If you are lucky you will find some bleed points. For instance our skin tank has some stainless bolts screwed into the top to let air out. Bleed points elsewhere will make life easier but I wouldn't expect to find many.

 

Good luck and wear your wellies.

 

Richard

[Bones]

I would.

 

This isn't an exact science. You have an engine for a car or lorry shoved in a boat with a made up cooling system and a tank of water shoved on the side. No-one sat down and designed this with a view to making it easy to maintain. As long as they could get the bits that were about right at the right price and they all fitted in the space, that is as far as it went. If it were a car then there would be a department to work on servicing and they would write a manual and maybe get the design changed. Here - it's you.

 

If you are lucky you will find some bleed points. For instance our skin tank has some stainless bolts screwed into the top to let air out. Bleed points elsewhere will make life easier but I wouldn't expect to find many.

 

Good luck and wear your wellies.

 

Richard

 

What do I do with the water that spills out? I persume I cant pump it out with my imaginary bilge pump (persuming it worked and was present and not imaginary at all) as coolant is pollution?

 

I doubt I will be even remotely lucky, but I do like messy, so this sounds like the perfect job for me.

Thanks

Edited October 13, 2008 by Bones

[RLWP]

What do I do with the water that spills out?

 

Wallow in it.

[John Orentas]

Hi Albie.

 

It probably makes little difference with a pumped system but generally speaking such systems should be complimentary to a thermal circulation, so the hotter water from the engine will cool as it passes through the cauli. as it cools it becomes less dense and sinks thus aiding the circulation.. So the rule is the hot water to the top, like a car or household radiator.

 

Looking at your post again, your system is much as I have described it but the circulation is opposite to your description. the hot water comes 'out' of the top of an engine.

[LEO]

Hi Albie.

 

It probably makes little difference with a pumped system but generally speaking such systems should be complimentary to a thermal circulation, so the hotter water from the engine will cool as it passes through the cauli. as it cools it becomes less dense and sinks thus aiding the circulation.. So the rule is the hot water to the top, like a car or household radiator.

 

Looking at your post again, your system is much as I have described it but the circulation is opposite to your description. the hot water comes 'out' of the top of an engine.

 

Sorry,

 

My error, the pipe connected to the bottom of the calorifier comes from a spigot off the rear of the cylinder head, not the engine block.

 

Albion

[Bones]

by jove, I think it worked!

[RLWP]

by jove, I think it worked!

 

Been paddling?

[RLWP]

by jove, I think it worked!

 

Come on now, tell your tale. What did you do, what did you find? There are people here who would like to learn from your experience.

 

Richard

[Bones]

Well, I did what it said on the tin... but I didn't get wet.

 

The system is a bit wild as it is, but I filled the top tank up and then wiggled the pipes around waited. Listened for some gurgling (which it did) and then filled it up again. I did this for a while, then when it stopped doing that, I traced all the pipes and found there were bits of pipe that had two connections - one where the coolant was entering/leaving, and another blanked off bit, so I undid the screws until water came out and did them up straight away. Wiggled the pipes some more, and then started the engine. I had a cauliflower full of hot water within 40minutes.

 

I did switch the Keel Cooler off, so the next trick will be to expose them and see whether they have any bleed screws, if not I will do the whole thing again with it on.

 

I did notice that the coolant on the engine has a spring on the cap - is that right?

 

The engine however sounds as though it has a bunch of nails in it.

[alan_fincher]

Bones,

 

You are probably not at great risk whilst living aboard, if you keep the boat moderately warm, but if you are putting significant water into the cooling system, don't forget you need to put some anti-freeze in too, before winter sets in.

[Bones]

I always put antifreeze in the water. When I say water I meant the proper stuff as in the mix.

[Tony Brooks]

Well, I did what it said on the tin... but I didn't get wet.

 

The system is a bit wild as it is, but I filled the top tank up and then wiggled the pipes around waited. Listened for some gurgling (which it did) and then filled it up again. I did this for a while, then when it stopped doing that, I traced all the pipes and found there were bits of pipe that had two connections - one where the coolant was entering/leaving, and another blanked off bit, so I undid the screws until water came out and did them up straight away. Wiggled the pipes some more, and then started the engine. I had a cauliflower full of hot water within 40minutes.

 

I did switch the Keel Cooler off, so the next trick will be to expose them and see whether they have any bleed screws, if not I will do the whole thing again with it on.

 

I did notice that the coolant on the engine has a spring on the cap - is that right?

 

The engine however sounds as though it has a bunch of nails in it.

 

 

If I have followed this thread correctly then the expansion tank is not pressurised and although its odd to be the engine tank you are sure it is.

 

Ideally the engine should run with the coolant under pressure but a BMC 1.5 in canal use will probably be fine without pressurisation. If the pressure cap is not on the expansion vessel it has to be on the "filler" cap on the manifold so yes, you should have the springy thing on it. However you should also have a large rubber "washer" between the springy thing & cap so it makes an airtight seal on the filler neck and the small tube sticking out of the side of the neck would ideally be connected up to the expansion tank. This way the expanding water goes back to the tank.

 

If a non-pressurised expansion tank is higher than the engine filler coolant will drain from the tank out of the filler as soon as you remove the pressure cap.

[Bones]

If I have followed this thread correctly then the expansion tank is not pressurised and although its odd to be the engine tank you are sure it is.

 

Ideally the engine should run with the coolant under pressure but a BMC 1.5 in canal use will probably be fine without pressurisation. If the pressure cap is not on the expansion vessel it has to be on the "filler" cap on the manifold so yes, you should have the springy thing on it. However you should also have a large rubber "washer" between the springy thing & cap so it makes an airtight seal on the filler neck and the small tube sticking out of the side of the neck would ideally be connected up to the expansion tank. This way the expanding water goes back to the tank.

 

If a non-pressurised expansion tank is higher than the engine filler coolant will drain from the tank out of the filler as soon as you remove the pressure cap.

 

 

Both are pressurised...

 

If I have followed this thread correctly then the expansion tank is not pressurised and although its odd to be the engine tank you are sure it is.

 

Ideally the engine should run with the coolant under pressure but a BMC 1.5 in canal use will probably be fine without pressurisation. If the pressure cap is not on the expansion vessel it has to be on the "filler" cap on the manifold so yes, you should have the springy thing on it. However you should also have a large rubber "washer" between the springy thing & cap so it makes an airtight seal on the filler neck and the small tube sticking out of the side of the neck would ideally be connected up to the expansion tank. This way the expanding water goes back to the tank.

If a non-pressurised expansion tank is higher than the engine filler coolant will drain from the tank out of the filler as soon as you remove the pressure cap.

 

It isn't....

[RobinJ]

Both are pressurised...

 

It isn't....

The expansion tank does not have to be pressurised, but they can be!

 

The connection to the expansion vessel may come from the overflow on the manifold/exchanger (e.g. when a rubber cap is fitted) - but equally they can be tee'ed into any of the plumbing (usually around the thermostat housing) and in which case I would expect the expansion tank to be pressurised!