Froggy

That's interesting because both pumps are Par Max 2.9s, admittedly of different vintage, and the potable water pump is noticeably noisier. Its ok, i have the original cover, i simply removed it for the photographs.

Ok, thanks, noted. As a temporary solution though, to save cash in the short term, i might have to bypass the Square D if it malfunctions again.

Ok folks, armed with the advice from this thread i took a closer look at the weekend. There was power going into the Square D but none coming out. However, when i pressed the contacts together the pump came to life and then operated normally for a few cycles of opening and closing a tap before playing up again on a couple more occasions. On closer inspection it looked as if there was some stubborn dust on one or two of the contacts, possibly remnants of spider web. I've cleaned the contacts up with some wet and dry and sprayed some WD40 into the works and things seem to be working normally again - for the time being at least. So, if i understand everything correctly, if the Square D plays up again i should be able to bypass this completely and just use the switch on the pump. Would i be able to use the Square D as a simple terminal block, i.e. wire the red in from the loom to the red wire out to the pump switch using one of the terminals on the Square D and likewise with the negatives on the other contact set (i.e. wire the two reds together on the far right hand side (as per the photograph at the top of the thread) of the Square D, and the two blacks on the far left terminal?). Would this be feasible? If so it would eliminate the need to change the wiring connectors, thus making it easier if i were to replace the Square D at a later date. According to the Jabsco Par Max specs the pump has both a separate switch and a bypass facility, so in theory both the Square D and the accumulator are not needed in the circuit unless i'm missing something.

Ours sometimes kicks in for a second or two. We turn it off at the panel switch at night to avoid being woken by it. But ten seconds would shift a lot of water so that would suggest, as others have said, a leak.

No, this was just a hypothetical situation where i had determined for certain that the existing pump was at fault and i had to replace it. I guess there is nothing to lose, as you say, in trying to bypass the cutout switch on the existing pump (which is well out of warranty since it was on the boat three years ago when we bought it) to see if the pump comes back to life. Thanks also for the additional information you provided re. the wiring setup and the effects of cycling, it has clarified things and it would seem that there is probably little to gain from replacing the pump, if this proves necessary, with a Par Max 4, which is best part of £100 dearer than a Par Max 2.9. It still begs the question though as to why a Par Max 4 was presumably used in the original fit-out, assuming the boat manual data is correct. I think i now have the information i need to ascertain what has failed in the circuit and i'll report back when i've had another look during the weekend.

Thanks again for your help everyone. Tony, I had a quick look at the accumulator and didn't notice a car type valve (the body is metal and i simply removed the nut on the top) but then i wasn't looking for one so will have another look over the weekend. So, given what blackrose says above, perhaps once i have got a working circuit i could adjust the cut-out pressure at the D switch or reduce the pressure at the accumulator to prevent cycling, or am i missing something here? The original fit-out of the boat did include a Par Max 4 (or at least, that's what the manual says, but i have previously noticed one or two discrepancies in it). However, apart from the cycling at the water filter the flow from the existing Par Max 2.9 was adequate, including when the shower was in use, and i guess that overall having a more powerful flow might just make it more likely to waste water. The boat started life in a hire fleet so perhaps the Par Max 4 was originally fitted on the assumption that there might be more demand on the circuit, for example somebody having a shower whilst somebody else was in the galley using the taps there. One thing that really confuses me though is that, if you cut the red lead at the pump switch and connect to the D switch, how does this setup provide a circuit to the pump? There is then no positive current going to the pump, only a negative out? What am i missing here? I'm at work atm so don't have the pump in front of me but isn't the red lead from the pump to the D switch the same lead that then runs to the back of the pump, otherwise what would be the point of the pump switch if the red lead bypassed it and feeds the motor directly? I'd need to be convinced that cutting the lead is a good idea because it would then probably invalidate the warranty.

Tony, many thanks for your detailed response - and also to everybody else who has contributed. I'm going to have a detailed inspection of the pump and switch over the weekend taking your comments into account, and will report back because it's the least i owe people who have taken the time to respond. I have a simple multimeter, and also still have the old toilet pump, which was removed due to leaking seals but still operated when i removed it. Unless there is a fuse within the motor then i don't think there is a fuse involved in the circuit, the 12v wiring in the boat uses circuit breakers and this definitely wasn't the issue (unless the breaker is faulty but i think this unlikely). Additionally, it's unlikely to be low battery voltage (which is what i first suspected) because i ran the engine to charge the batteries up and it didn't resolve the problem. I'm also pretty sure that the pump switch hasn't been bypassed, the original wiring appears to be intact including the red lead running down the body of the pump. I can see what your saying regarding the pump cycling, Tony, when the water filter tap is used, but do you think replacing with a Par Max 4 would be of any use, given the cut-in and cut-out pressure specification is i think the same as the Par Max 2.9? I'm guessing that it would chuck out larger volumes of water per cycle (and so require less cycling for a given quantity of water) but would still actually cycle. What do you think? If this is the case, i'm not sure that the extra £100 for the Par Max 4 can be justified. However, according to the boat manual it was originally fitted with a Par Max 4. David Mack, i have to admit that i don't have any knowledge with regard to the accumulator. How would i test for correct pressure? I haven't taken it apart but there doesn't seem to be any obvious way on the externals of the unit for adjusting pressure. I don't fully understand why this component is even required when the toilet pump circuit doesn't incorporate one, would i be correct to assume that if's solely for the purpose of activating the switch when taps are opened? If this is the case could an airlock possibly be the problem and is this an increased possibility due to a period of inactivity during hot weather? We've had the boat for over three years now and have never experienced such a problem before. Finally, would i be correct to assume that the vertical blue component in the top picture is a filter? If so i guess that this may require cleaning since it's never been done whilst we've had the boat. Having said that the water tank is stainless steel and so i wouldn't expect much debris to get into the pipes. The red button on that unit appears to be a bleed button; i've operated this a few times but it hasn't resolved the problem.

Hi Our potable water pump is inoperative. It's the one on the left in the photos. There's no life in it at all. What are the chances that it's definitely the pump, or could it be one of the other components in the circuit, and if so what would be the best way to identify the faulty component? I'm pretty sure it's not the on-off switch on the control panel because it worked briefly when turned back on and then failed without this switch being operated again. The pump wasn't used for a few days in hot weather, so is it possible that it could be something as simple as an airlock? The pump in situ is a Jabsco Par Max 2.9. I replaced the other pump in the photograph (for our pumpout toilet) a couple of years ago with the same model following advice from this forum. If i need to replace the potable water pump would there be any advantage in upgrading to a Par Max 4? We have a drinking water filter in the circuit in the galley, when this has been used the existing pump has worked in fits and starts, i.e. cut out and restarted at intervals of approx 2 seconds due, i'm assuming, to the pressure switch either in the pump or the separate switch in the circuit; this also happens when taps are only turned on to a low dribble and might possible have shortened the life of the component that has failed. Given that the pressure cut-in and cut-out specifications of both the Par Max 2.9 and 4 are identical, would upgrading to a 4 make any difference to this issue? Thanks in advance.

I'll try to look in this evening, especially if there's some real ale going.

1 hour ago, TheBiscuits saidaid: Ah, but did you ever name the expansion bottle? I suggest calling it Ed Urtank. 1 hour ago, TheBiscuits said: Ah, but did you ever name the expansion bottle? I suggest calling it Ed Urtank Ah, it's pretty clear that you lot have very little to do atm so have wandered over from the Skippers Wanted thread.....

Thanks, but this has now been sorted as per later posts in the thread.

I guess i should have known better than to have stirred the pot!

Thanks. I've taken a chance and ordered a copy of the manuals; if they help me to see how they are put together it might make it easier to take a few panels off to reach the thermocouples and thermostat. I probably wouldn't remove the thermostat myself but i can at least check there are no obvious mechanical issues with both that and the thermocouples and give everything a good clean up. As for the GAS website, you are right, their prices are very good, but unfortunately everything they list is shown as out of stock! I doubt they will be getting more in. Fortunately, there are still a few websites out there that do carry stock.

I think i was spared those!

Just as i thought. This is still a very silly thread.