No hot water?

[junior]

For the first time since owning my boat I have no hot water.

 

I have a Petter PH2W raw water cooled engine that heats the calorifier. It is my only means of water heating until I light the stove.

 

It has been like this for 2 days cruising. Normally the hot water coming out of the tap would be too hot to touch. For the last 2 days after long 10hr days it has been less than luke warm and this is definitely not normal.

 

2 days ago I drained the yukky potentially 20 year old water out of my back boiler system (back boiler, 1 radiator and the calorifier) and replaced it with 50/50 antifreeze/water. I'm sure this must be a coincidence as in my limited (I.e. none) knowledge of this sort of thing the engine circuit and backboiler circuit are seperate. It does seem strange that having worked perfectly since day one of the boat it should go wrong at the same time.

 

So having never had this problem before, I don't know where to start looking. Any suggestions or advice? Can supply more info or photos on request.

[Naughty Cal]

Air lock?

[davidc]

Have you checked the thermostat it could be corroded or blocked .

 

the thermostat should start to open at 155/165F(68/74C), and it should be fully open at 185F(85C).

[magnetman]

Is it a horizontal calorifier?

 

Calorofiers regularly get air locks in the coil. I'm not entirely sure how to get the air out if it is a horizontal one. My (vertical) calorofier currenly has air somewhere in the coil connected to the engine but as I have 3 other sources of hot water I haven't bothered sorting it out.

[The Bagdad Boatman (waits)]

1 :The pipe from the engine to the calorifier should be hot, if not the problem is low water in the engine or failed engine water pump.

2: if that is ok then there is an air lock in the calorifier so the engine is warming air instead of water in the calorifier. air is always at the top so find a high point in the system and let the air out.

[Captain Fizz]

Morning Martin,check the intake water filter and the water pump impeller.

If they are both clear, see if there is an air bleed at the top connection of the engine circuit coil in the calorifier. If there is no bleed point, just crack the connection and bleed it there.

Sounds like you're having a great trip!

[David Mack]

Did you premix the antifreeze and water?

[magnetman]

I wonder if the stove and the engine are going through the same coil in the calorifier? Not sure how this would work as I have always had twin coil setups.

 

[MtB]

I can't see how draining and refilling the stove back boiler circuit can prevent the engine cooling circuit from heating the calorifier. They are, or should be, completely separate circuits.

 

Unless Junior's system is old and non-standard, and shares the same water. In which case Rachel is probably right. But this seems unlikely as she isn't usually

 

So Junior, is your engine coolant circuit separate or does it share the back boiler water? Does your calorifier have one or two heating coils?

 

 

MtB

[mattlad]

Is the (coolant) water pump working?

[junior]

I'm just preparing to go down the boat lift onto the river but will work through questions 1 by 1.

[junior]

Is the (coolant) water pump working?

My only way of knowing is to look if there is the usual amount of water coming out the side of the boat, and there is. It's only a trickle, but it's only ever been a trickle. If the water pump wasn't working I guess my engine would overheat? I've no temperature guage, but I've just done 2 ten hour boating days so if it wasn't working I reckon I'd know about it.

 

Just uploading pictures of my calorifier. I think it is an upright twin coil.

[junior]

Bottom plastic pipes are from the engine. Top 2 are the back boiler circuit.

[matty40s]

Bleed the top brass valve next to the toilet roll.

then also check the top of the calorifier to see if there is a bleed valve there.

If there are isolation taps to your back boiler system, close them as you may be using the engine to heat the rads and backboiler now you have a clean system.

[junior]

Bleed the top brass valve next to the toilet roll.

then also check the top of the calorifier to see if there is a bleed valve there.

If there are isolation taps to your back boiler system, close them as you may be using the engine to heat the rads and backboiler now you have a clean system.

The radiator is cold so I don't think I'm heating that circuit from the engine.

 

I do have a twisty plastic know on the very top of the calorific. When I twist it I get a gurgling bubbling sound from in the calorific. Should I undo that brass tap thing with the engine running or not?

[Naughty Cal]

I can't see how draining and refilling the stove back boiler circuit can prevent the engine cooling circuit from heating the calorifier. They are, or should be, completely separate circuits.

 

Unless Junior's system is old and non-standard, and shares the same water. In which case Rachel is probably right. But this seems unlikely as she isn't usually

 

So Junior, is your engine coolant circuit separate or does it share the back boiler water? Does your calorifier have one or two heating coils?

 

 

MtB

Course I am

[David Mack]

My only way of knowing is to look if there is the usual amount of water coming out the side of the boat, and there is. It's only a trickle, but it's only ever been a trickle.

What temperature is the water coming out of the side of the boat? It should be almost too hot to put your hand in if its going to heat the calorifier.

 

Ans what temperature is the pipe which runs from the top of the engine to the upper coil connection on the calorifier? That too should be pretty warm.

[Machpoint005]

My first thought was to wonder if a stopcock or valve previously open is now shut? (or arsy-versy).

Always look for the simple reason first!

[matty40s]

 

I do have a twisty plastic know on the very top of the calorific. When I twist it I get a gurgling bubbling sound from in the calorific.

 

You need to keep it twisted until the gurgling bubbling sound becomes visible water.

[MtB]

Course I am

 

Junior's photo demonstrates you're wrong. As usual!

 

 

MtB

[LoneWolf]

For the first time since owning my boat I have no hot water.

 

I have a Petter PH2W raw water cooled engine that heats the calorifier. It is my only means of water heating until I light the stove.

 

It has been like this for 2 days cruising. Normally the hot water coming out of the tap would be too hot to touch. For the last 2 days after long 10hr days it has been less than luke warm and this is definitely not normal.

 

2 days ago I drained the yukky potentially 20 year old water out of my back boiler system (back boiler, 1 radiator and the calorifier) and replaced it with 50/50 antifreeze/water. I'm sure this must be a coincidence as in my limited (I.e. none) knowledge of this sort of thing the engine circuit and backboiler circuit are seperate. It does seem strange that having worked perfectly since day one of the boat it should go wrong at the same time.

 

So having never had this problem before, I don't know where to start looking. Any suggestions or advice? Can supply more info or photos on request.

 

this topic comes up fairly regularly on here - i suggest you do a search

[magnetman]

Its a pressure relief valve I imagine.

 

When you twist it the domestic water pump should run as it is the same effect as opening a tap. There should therefore be water coming out - it might be plumbed to a skin fitting in the hull side. If it hisses and gurgled but no water then the calorifier is not full (fresh water)

That would be a bit odd if it happened the same time as the back boiler heating circuit being drained... if they are related.

 

I once had a calorifier with a small leak in one coil which resulted in the engine header tank overflowing because the domestic pump pressure forced fresh water into the coil which directly communicated with the open vented header tank.

 

Edite typeo

20 years. Is that 'getting on a bit' for a calorifier?

Edited September 10, 2014 by magnetman

[junior]

Sorry for sparse info/updates. In amongst posting etc I've negotiated the Anderton lift for the first time, visited Yardwoods Basin and somehow ended up in a Weatherspoons

 

However, I've opened that brass tap thingy on the top of the two plastic pipes and I had about 10 seconds of air/steam coming out and then I got hot water.

 

So I guess that means there was an air lock? I won't know for sure if this has solved the hot water problem until I cruise down to Winsford tomorrow. Hopefully I'll have a calorifier full of fresh hot water.

Edited September 10, 2014 by junior

[smileypete]

Good to hear it's OK.

 

Worth checking the expansion tank level, if below min more air may get in.

 

cheers, Pete.

~smpt~

Edited September 10, 2014 by smileypete

[junior]

Good to hear it's OK.

 

Worth checking the expansion tank level, if below min more air may get in.

 

cheers, Pete.

~smpt~

The only expansion tank I have is on the back boiler circuit and (as in a separate recent thread) I've drained that and refilled it with fresh coolent/water mix. Until I light the stove up I won't really be able to clear any air or adjust the level in the expansion tank.