Replacing a water pump

We have had a problem with our water pump for quire some time, in fact it has been going off unexpectedly since 2020 and we mention it in our watermaker video. Since 2020, we fixed the issue of the water pump going on at random times by the simplest solution yet and that was simply turning the pump off when we were not using it. For the last few months the issue has got steadily worse with the pump going on more frequently when not in use, what we think it is, is leakage of some sort. So when the tap goes on, the pressure drops which is detected by the pump and the pump goes off. Beverley theorised that the valve between the high pressure side of the pump, the side with the taps, and the low pressure side of the pump, the side with the tanks, had failed so water was leaking out which is why the pressure was dropping and the water pump would go off unexpectedly. Equally if there is a leak on the high pressure side then again the pressure will drop Whatever is going wrong, it has got worse which is why the pump firing frequency has increased. From our investigations to date, it is the pump that has the issue, so we thought that the simplest solution was to replace the water pump.

The pump that we purchase was as near identical to the one we were replacing, but for the same flow rate, the new pump was only taking 4amps as opposed to 7.5Amps. So with nearly 1/2 the power consumption, we had high hopes of the new pump. For the change over I thought that we would need to drain the tank, while Beverley was all for putting a wooden bung in the pipe and leaving the water in the tank. Seeing as Beverley was actually doing the job, we were going for the bung method. If I was doing the job then I would of drained the tanks. This is how it goes in Salty Lass, the person who is doing the job decides what tasks get done.

One of the things that I failed to do was turn the pump off, so as soon as Beverley had unscrewed a hose fitting, the pump went off, I soon fixed that and turned the pump off. Once the hose was detached she simply put in a bung so that no water came back up from the pipe.

While we were investigating the wiring we realised that the connections had simply been covered with PVC tape. It did mean that we could simply swap out the wiring, so that was good. All I had to do was make sure that the connections that I crimped to the new pump were the same type as those on the new pump. We also improved the look of the connections by using amalgamating tape where required.

One of the other things that we did before replacing the pump was check that the hose fittings were correct and we would be able to fit everything as it was.

Once the pump had been removed I looked at the old pump and cleaned the filter on the low pressure side of the pump. Inside was a whole load of sealant that had clearly got trapped inside the filter. Once Y had cleaned the filter, we simply pit it onto the new pump.

Fitting the new pump was really easy, and all that was required was drilling two new holes as the base of the new pump was slightly wider than the old pump. The fun and games came from the testing, as we seamed to have lost the gasket on the hose fitting on the high pressure side with the result of water leaking out into the bilge. So Beverley took one of our gaskets from the engine spares and used that. Fitting the gasket meant that she disturbed the hose fitting so that had to be redone, but once she had done that, there were no more leaks. Once the pump was fitted, she did have to adjust the pressure setting on the pump, so that the flow at both the galley and the heads were good. To adjust the pressure there is a small screw at the bottom of the pump and that either decreases of increases the pressure provided by the pump. The setting straight out of the box had been at the lowest setting.

With the old pump removed, I decided to clean the pump us so that it could become a spare. The new pump had cost £60 so getting an engineer to clean it up would not be cost effective, but I had the time, so I was willing to do it. Beverley has been watching mechanical videos and one of there top tips is undo the crustiest screw first. With the use of power tools we soon had the pump in bits. We enjoyed taking the pump apart, and we cleaned it with vinegar to remove the calcium deposits and brake clearer everywhere else. Brake cleaner is very flammable, so if you do use this compound make sure you open your hatches.

After we had cleaned the pump, we tested it all out to check that we had a serviceable spare.

Raising money for the RNLI

The RNLI turned 200 years old on 4th March 2024. So as sailors and people who promote the joy of sailing, we thought that we would like to raise just £200. What we hope is that other people take up the shout and raise their own £200. In the last 200 years the RNLI have saved over 144,000 lives and yet they are funded entirely by people like you. They are not government funded.

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