Replacing Calorifier - Stupid Questions!

[CaptainBob]

Last time I posted in here about plumbing, my question was so daft that some people suggested I ought not be allowed to be in charge of a boat! Since then I've successfully logged a lot of problem free hours aboard my boat - but done no more plumbing.

Now unfortunately the time comes again for me to return to plumbing. Please go easy on me!

The calorifier in my boat is leaking and it's old so I've bought a new one which will fit in the same space.

New one has 1/2" male threaded connectors for all 4 connections. Old one has male pipe stumps onto which pipes which are exactly the right length, just, are jubilee clipped.

I've three problems (that I know of):

1. How do I connect these pipes to my new male threaded connectors? I can't find parts on the net for this (don't know where to look/what to search for) - and the new device does not say what thread it is other than (1/2" threaded), so I don't know if it's NPT or what.

2. The pipes in the boat are not long enough to reach the new connection points I don't think. They are however threaded through all sorts of parts of the boat so I don't want to buy whole lengths of new hose - I'd prefer to just extend them if possible. How? Or is this bad?

3. Old and new calorifiers are/will be installed horizontally. Not worried about the domestic water side of it, but the engine cooling side - as soon as I take off the existing pipes they'll take in air, lose coolant, and the new calorifier will have no coolant in it - how do I bleed the air from the system? Should I fit a temporary header tank (or something) to do this - there is not one in place now, and no room for one insitu with enough height to get above both tank and engine. And the engine is approximately at the same level as the tank is.

Thank you!!

 

[VicS]

Most likely the thread is BSP if you have bought it in the UK

1/2" npt and 1/2" bsp have the same thread pitch and to some extent are interchangeable. IIRC there is a small diffrerence in diameter which means that BSP has to be tapped out to fit onto a NPT thread ( or is it the other way round?)

Probably you will need Female sockets and male threaded hose tails but note there are some female threaded hose tails listed as well.

If you need to extend hoses then straight hose connectors eg these might do the trick.

 

[nimbusgb]

You'll need to buy a roll of ptfe thread tape to seal the threads of the joints. There's a knack to applying it to the male threads. Takes seconds when you know how.

 

[VicS]

4 mil. teflon tape?

Some weird American unit I guess 'cos its ceratinly not 4 mm thick !

 

[KAL]

When I did ours a couple of winters ago, I had the same problems. I used push-fit connectors to adapt the existing pipe. Where this didn't work, I used jubilee clips to attach flexible hose to the old piping and the new calorifier male connections.

The engine cooling circuit did not need bleeding. It continues to function as normal.

 

[Stu Jackson]

Recognize that if your heater connections are at the lowest point of the freshwater coolant in your boat, then that is where the coolant will be! If it was my boat, then I'd drain all the coolant from the engine first, to save as much as you can. I had to replace the hoses from my engine to the heater once.

Like this: http://c34.org/bbs/index.php/topic,3769.0.html

Depends on what you bought and what pieces you need to make the connections. Find the right bits and then cobble it together.

Engine cooling side: you have to BURP that side. The idea is to FILL the new hoses and the heater with coolant to make sure they are full before you start your engine or else it will or might overheat.

 

[CaptainBob]

Thanks for all the replies. I've bought some bits from ASAP now (thanks for that Vic) and think I know a way forward. I love this forum!