Un­der­floor pipes are an is­sue

Canal Boat - - Back Cabin - GLYN WHITE, via email TONY REPLIES…

QWe have a leak in our cen­tral heat­ing sys­tem. Af­ter we switch it off, it takes about two hours to lose five litres. The pip­ing is un­der the floor, so it is not sim­ple to find. One sug­ges­tion that’s been made is that we sim­ply re­place all the pipes – but I would have thought that a me­chanic, prob­a­bly test­ing pres­sure drops around the sys­tem, would be able to lo­cate the length of pipe that has the prob­lem.

AFirstly, wa­ter ex­pands when heated, so if you fill it to the brim when cold it will leak out as it ex­pands when warm­ing up, then the level will drop as it cools down.

Pas­cal’s law says that pres­sure is equal through­out an en­closed sys­tem, so there is no way one could use pres­sure to lo­cate a leak.

If it re­ally is a leak then you should find plenty of wa­ter with an­tifreeze in it in the boat’s bilge – do you? It could also be in the boiler’s heat ex­changer.

I don’t un­der­stand why boat-fit­ters try to hide all the ser­vices un­der the floor: it makes fault find­ing so much more dif­fi­cult. If I was sure there was a pipe leak, I would do as sug­gested and re-pipe the sys­tem above the floor (box in if you like, but make sure the box­ing un­screws and lifts away).

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.