Monday, January 09, 2017

An easy run up Grindley Brook and a leak cured–hopefully!

We came up Grindley Brook Locks yesterday, giving me the afternoon and today to pull out the calorifier (again…) to resolve the domestic water leak that has plagued us for a week.

It was a steady trip up the locks, we were following a boat that had gone up earlier so I had all the locks to turn. But even so we were filling up with water above the locks by twenty past eleven.

Under the fine blue-brick short tunnel through the disused railway embankment below the locks.IMG_3224

I had to avoid two anglers who’d taken up residence on the lock-landing below the bottom lock, leaving me no place to tie up, but I managed by emptying the lock with the our bow-fender nudging up against the lock gates.
No big deal; I‘d probably have done that anyway but I did point out to them that it wasn’t the best place to occupy.

Coming up the third and last single chamber…

…and into the bottom of the triple staircase


Coming up the top chamber of the staircase.
The very nice lock-keepers house is now a private residence.

We filled up the water tank then moored up a quarter-mile or so further on.

Now then, that leak…
I lifted out the calorifier again, an easier job now that I’ve re-organised the plumbing and fitted service valves everywhere!

Water was dripping from near the bottom-most fitting, the one I’d resealed last time. But instead of coming out of the joint as I thought, cutting back the lagging showed it was actually appearing from between it and the copper cylinder.

Coming from there it could be a leak anywhere on the unit… so I set to and removed great chunks of the lagging. There was evidence of an old leak on the front end…
…but the lagging was dry at this end, unlike the other.
Finding nothing obvious I removed and refitted all the connectors, then shoved it back in and filled just the domestic, leaving the heat-exchanger coils from the engine and heater till I‘d proved the main chamber out. All seemed well, no leaks after half an hour so I reconnected the pipework from the Webasto heater and fired it up. It took a while for the stone-cold water to start to warm, but when it did and the cylinder expanded, a fine spray of water started squirting from the seam towards the back end.  Aha!
It was getting on by now so I drained down again (you can see why I wanted to fill the water tank, the calorifier holds 12 gallons and I’ve refilled it 3 times…) then left it till today.

IMG_3237This morning I rotated the tank on it’s axis to get to the seam and polished it up with wire wool.

There was a very fine black line just above the seam, it would be this that opens up when the tank heats up.
Out came the blow-lamp, flux and solder and I effected a repair, not the prettiest but it turned out to be effective with everything filled and heated up.


I was planning for this to be a stopgap repair, just until I can source a replacement of the same design. But then I noticed the pressure gauge on the pressure relief valve.
As the system is pressurised by the water pump, it has to be sealed but to prevent damage to the plumbing and components it has this pressure relief valve that is supposed to limit the pressure to 3 Bar, opening at that point and venting the excess through a pipe to the outside. With the engine and the Webasto both running and heating up the tank, the expansion of the water had pushed the pressure right up, the needle hard on the limit pin on the gauge!

The calorifier, when new, was certified to 5 Bar, but with the PRV not working it looks like it’s regularly been close to that, and it’s over ten years old now.  So I reckon that a new PRV to limit the pressure, the repair, and the rest of the tank, should be OK. Fingers crossed. So I‘ve a new PRV of the same design coming Click and Collect from an ebay supplier to Argos at Whitchurch. Till then we’ll have to open a tap to relieve the pressure every twenty minutes or so while the engine is running.
With everything dry I had an interesting few minutes reassembling the pieces of lagging I’d removed, and sticking them back on with that handyman’s friend, duct tape. It’s ages since I’ve done a jigsaw…

Hopefully that will be the last time It has to be out, for a while anyway. I know, tempting fate. I did say hopefully.

Not sure what we’re doing tomorrow, but whether we move or not we’ll have to reverse a short way to fill the water tank again.

Locks 6, miles ¾    

1 comment:

Paul (from Waterway Routes) said...

Once the water is hot you don't need to keep opening the tap as it will already have expanded. Opening a tap is likely to allow more cold water in which will then expand and repeat the problem.

Did you fit a pump for free central heating while you had everything out?