Does it sound like I have a burst pipe?

[RosieP]

Hello,

 

I've just come back to my boat after a week away over Christmas. We are in the south east so no snow but freezing conditions. Before leaving we drained all water out of the taps, assuming this would drain the calorifer too. I am now trying to fill back up but I'm a bit concerned as the water pump has been going for about 2 hours and only deactivates when turned off. This makes me think we must have a leak somewhere and its pumping water into the hull. Or, I'm over worrying and its just taking a long time to refill the system. I stopped filling up the tank when it was about half full as I worried I was just pumping it straight out into the hull. It now sounds like the tank has gone down a lot when I tap it.

 

Does anyone have any ideas how to get a good diagnosis?

 

Thanks very much.

[MtB]

I fear you are right.

 

The other possibility is the pump is air locked or the pipe feeding it is still frozen. That would give the same symptoms.

 

The only way to find out for sure is to disconnect the outlet pipe from the pump and see if it is pumping water or fresh air.

 

 

MtB

[Bobbybass]

Am I stating the obvious...?

Look down your cabin bilge and see if there is water...?

If its been pumping as much as you say..you can't miss it.

[MtB]

Am I stating the obvious...?

Look down your cabin bilge and see if there is water...?

If its been pumping as much as you say..you can't miss it.

 

 

Indeed. After two hours of pumping there could easily be a whole tankful in there....

 

 

MtB

[Bobbybass]

Sounds like you did your best to drain it...but you can never be too careful.

 

My neighbour drained his system from a low floor mounted drain point...but didn't open his kitchen taps !!

When he returned...they looked like Desperate Dan's gun......splayed at the ends...where they had a small amount of water in the tap body.

[Guest]

Hello,

 

I've just come back to my boat after a week away over Christmas. We are in the south east so no snow but freezing conditions. Before leaving we drained all water out of the taps, assuming this would drain the calorifer too. I am now trying to fill back up but I'm a bit concerned as the water pump has been going for about 2 hours and only deactivates when turned off. This makes me think we must have a leak somewhere and its pumping water into the hull. Or, I'm over worrying and its just taking a long time to refill the system. I stopped filling up the tank when it was about half full as I worried I was just pumping it straight out into the hull. It now sounds like the tank has gone down a lot when I tap it.

 

Does anyone have any ideas how to get a good diagnosis?

 

Thanks very much.

Sounds very much like it. There is no way it should take that long to re prime the system. However you may not have actually 'burst' a pipe you may be lucky (depending on what has been used) and the expansion may just have pushed a connector off, which is relatively easy to fix if you can get to it.

[nicknorman]

2 hrs is far too long, should be more like 2 minutes. Check under the flooring near the back, I think you will find water. There is it much to be done except check all the plumbing. If it is plastic plumbing, it will probably be fitting that has been pushed off, rather than a burst pipe.

 

Things to check : you HAVE turned on the water tank stopcock haven't you?

 

Check for water under the floor - if none after 2 hrs, the pump is perhaps not pumping. If you open a tap, does water come out when pump runs?

 

If no water under the floor and the stopcock is on, possibly the tank outlet is frozen or blocked.

[alan_fincher]

it is hard to see how just opening your taps will ever drain your calorifier.

 

Most caloirifiers are lower down than most taps, and water doesn't flow uphill unless sucked, or pushed by something.

 

Unless many gallons of water came through the taps, even though you had the pump switched off, you have not drained your calorifier.

 

However it is highly unlikely to be the calorifier giving your current problem, (if you actually have a leak). It is far more likely that a high up joint in your system has frozen, and eitherr split, or just forced itself open.

 

Sadly, I think there is now a distinct possibility there is lots of water under your floors. If your boat is even slightly front end higher than back end, you need to be looking under the floors in the back end.

[Guest]

Not withstanding of course that the water has a way to find it's way to the stern and the flow is not obstructed by a joist, which is not unknown.

[MtB]

it is hard to see how just opening your taps will ever drain your calorifier.

 

Most caloirifiers are lower down than most taps, and water doesn't flow uphill unless sucked, or pushed by something.

 

 

 

And set against that, the calorifier is such a huge volume of water it will take days or weeks to freeze in intermittently subzero conditions long after all the little pipes have frozen and burst.

 

MtB

[alan_fincher]

Not withstanding of course that the water has a way to find it's way to the stern and the flow is not obstructed by a joist, which is not unknown.

 

Not unknown, and if there is a load of obstructing ballast on the baseplate, that can also slow down the rate at which water makes its way to the lower end of the bilge.

 

The reality is though, if it is a relatively modern build of a normal type, there are likely to be gaps at any "joists" that are transverse across the boat, and it is highly unlikely that the likely quantity of water being talked about here will remain in a "higher" bit of the bilge, and not drain backwards.

 

Obviously not always the case - one of our historic boats has continuous knees that run down one side, across the bottom, and up the other. These sit approaching maybe a couple of inches above the baseplate, so puddles stay formed ahead of each knee. However such construction is highly unlikely in a modern build.

 

All that said, if this is a failure of a pipe joint, as I would say is most likely, that pipe joint is probably "visible" if you follow the pipe runs, and look for somewhere where water is spraying out. It's just that "somewhere" may be under a sink, washbasin, bed, etc, or maybe on a shower mixer tap, or similar. If you can't get under the floors, I'd start following the pipe runs. You'll need to do that anyway, if you do discoer water under the floor, because ultimately you have to find where it is coming from.

[MtB]

Given the extremely low temperature overnight my money is on a frozen pipe feeding the pump.

 

That isn't to say that when the pump feed is restored there won't be some burst joints too...

 

 

MtB

[dor]

Depends on the pump, but I let mine pump air for a minute or two to clear water from the pipes if I am doing a full winterisation. This will also put a bit of air into the top of the calorifier, but as it sits on the swim it is protected to some extent. Didn't have any issues after many days at -15 or less.

[Robbo]

 

The other possibility is the pump is air locked or the pipe feeding it is still frozen. That would give the same symptoms.

 

 

If my tank and pipes are empty my pump will just keep going, it's not until I open a tap so the air can escape and the system can then fill. So to the OP, I would open a tap, if you get air or splutters of water keep the tap open until a flow of water comes out, the pump should then switch off shortly after switching the tap off.

[Paul C]

To point out the obvious...... 1) is there water in the tank 2) if there is, use a dipstick to monitor the level while the pump is running. If it gradually depletes but the calorifier isn't filling/no water is coming from taps, then there is a leak and its ending up in the bilge. 3) its quite possible that the boat has an auto bilge pump which will make looking in the bilge for a tankful of water an unreliable indication of a leak (but looking at the bilge pump outlet, hearing its operation, or a look in the bilges is still useful).

[RosieP]

Hiya,

 

Thanks for all your replies. There is no evidence of any water in the bilge, either at the stern or mid-way down the boat. One possible clue is that the pump is still running even when we've isolated the tank at the stop cock, and so no water is running through the pump and it still activates. This shows that the pump running doesn't indicate water running out of the tank. Mike - my money is on your suggestion, frozen pipe feeding the pump and fingers crossed there's no other burst pipes.

[Graham Davis]

Is it possible that the impeller has broken off the shaft, or stripped, due to the pump internals being frozen?

[Neil Smith]

Undo the pipe feeding the pump and connect a temporary pipe to it and fill pipe with water, now turn on pump and see if it pumps.

 

Neil

[alan_fincher]

Is it possible that the impeller has broken off the shaft, or stripped, due to the pump internals being frozen?

 

Very few of them have an impeller, do they? Fresh water pumps are mostly diaphragm types, surely?

[Keeping Up]

Hiya,

 

Thanks for all your replies. There is no evidence of any water in the bilge, either at the stern or mid-way down the boat. One possible clue is that the pump is still running even when we've isolated the tank at the stop cock, and so no water is running through the pump and it still activates. This shows that the pump running doesn't indicate water running out of the tank. Mike - my money is on your suggestion, frozen pipe feeding the pump and fingers crossed there's no other burst pipes.

It's perfectly normal for a pump to run when the stop cock is closed, because there's no water to build up the pressure that it needs to operate the cutout switch.

[blackrose]

One possible clue is that the pump is still running even when we've isolated the tank at the stop cock, and so no water is running through the pump and it still activates.

Yes, a fresh water pump with a pressure switch will always cycle and sound like it's pumping water if can't get any. So it will do the same thing when the tank is empty. It's not a good idea to leave it running like this for too long though.

 

Edit: just read Alan's post which says the same thing.

Edited December 31, 2014 by blackrose

[RosieP]

Thanks everyone. The running pump was a red herring - no leak. As suggested by the previous posts the pump will run even when no water circulating. we took the pump apart and it was clogged up with rust and limescle - declogged and now we have water in the taps once again. Phew!

[Neil Smith]

I would put in a filter if you are getting crud and rust in it as its much easier to clean out.

 

Neil

[Drayke]

As Neil said, plus it maybe that you may need to clean and repaint the inside of you water tank.

 

Regards

 

Fred.

[Neil Smith]

That's assuming its a built in one with hatch and not stainless or plastic with no hatch.

 

Neil