Tuesday, 11 February 2014

Header tank losing water - something to fix

I think I've mentioned this before: I keep finding the central heating header tank on Jubilee dry. This is after spells of a few weeks' absence from the boat. It has taken about five pints of water/antifreeze to top it up each time, so it's leaking out somewhere.

I have taken advice from Tony Brooks, who suggests checking all the pipework joints, looking for evidence of antifreeze staining on surrounding woodwork. From memory (I'm not on the boat at the moment) most of the pipework is copper. If there are plastic sections, then a special stiffening section should be present where a compression joint is made, to prevent the joint coming loose.

I have not noticed any water in the cabin bilge, so it's a mystery as to where all the water is going.

Another TB suggestion is to pressurise the system to about 10 psi*, and then any leak should be more obvious. As far as I remember, though, the central heating pipe runs are hidden below the floor. Without pulling up the floor - oak strips - how am I to find a leak down there?

All being well, we should be on board in a week's time or so, so I'll make a determined effort to sort this out. This will be helped by the fact that Ally and Ben have started to remove some of their possessions.

*according to TB: Pressurising can be done with specialist equipment, or by screwing a lorry-type tyre valve into the cap of the header tank and using a bicycle pump.


Nev Wells said...

I might have commented before. on Waterlily we had a separate vent pipe that had a simple open/close plastic valve on it this ran from the engine hole up the side of the semi trad and out via a hole made in the side. The frost got to this valve and damaged it. The resultant effect was coolant loss the , slowly emptying the header tank. I convinced myself the pipe work in the Calorifier had a pin hole in it and the water was being lost into the hot water cylinder, as the central heating pipes routed through the cylinder to heat the water if needed. ( slow)and I could not find the lost water I replaced the Calorifier then later found out the real cause !

Halfie said...

Nev, as far as I can tell it's a closed system with no vent pipe to the outside. But I will check again next week. Thanks.

Glyn White said...

Hi Halfie, we are having a similar problem with our central heating system. Before we run the system, we have to put five litres of water in the tank. Once the system is switched off, that water is lost, over a coupe of hours. How did you trace your problem, and how did you fix it. Our pipes are also under the floorboards, so hard to access.

Any help appreciated.
Evelyn and Glyn
NB Lunas

Halfie said...

Hello Evelyn and Glyn, I have to admit that I took it to a boatyard for them to fix. (Grand Junction Boat Company at Gayton Jn - they were good.)