Sam T

I see. I had misunderstood the purpose of the test you were suggesting and (evidently) how voltage drops work. The 12.5 down from 12.8 at the battery is in line with how it's always been when the pumps been working properly. But I understand I haven't come close to ruling out volt drop as an issue, so will investigate further. Thanks.

Right I see. Thank you for clarifying

I've been messing around with a volt meter this evening. There's definitely a reading of 12.8v at the point the pump connects, so there's not a voltage drop between there and the batteries. But it's not very accessible, so very tricky to get a reading at the motor with it connected and running. The voltage across the batteries drops to 12.5 with it running, but never below this, even when it's making the sluggish sound. With some rearranging and moving of wires I could get a reading at the motor with it running, but realise I'm not sure what this would tell me. If it was drawing more amps than it should be, or the voltage reading was unexpected, this would just confirm that I need to replace the pump, or am I looking for anything else? I'm leaning towards replacing it anyway, which will probably solve any issue, but if not, I will continue diagnosing and at least I'll have a spare for next time. I would like to get away from relying on the inbuilt switch if it is prone to fail, but think I need to improve my understanding/get someone to come over and guide me through this as a longer term aim. My knowledge/ability is pretty shaky at the moment!! Thans for all the useful comments.

Good idea, will have a play this evening

Good thought on the batteries, but I don't think so this time. They were still showing 12.8 long after dark last night having noticed the issue in the afternoon so I think I'm in the clear there Thanks, will look into this in more detail

Thanks both Buying a spare pump to swap in when it fully gives up is easy enough! Appreciate the helpful advice as always.

I have a flojet pump and accumulator set up on my narrowboat. I put the pump in 2 years ago (with v helpful advice from people on this forum!!) and has worked perfectly since. It's still working fine, but the noises it makes have changed slightly. I'm wondering if it's symptomatic of anything, or maybe implies it is about to fail. It cuts in as usual when a tap is open and the accumulator pressure drops low enough. It then continues for 10s or so after a tap is closed as it should, still sounding normal. For a few seconds before it cuts out again it suddenly starts sounding a little bit sluggish (like its working less hard if anything), sometimes flicking between this sluggish sound and normal before then cutting out. It does always cut out in a reasonable (and it's usual) time frame so don't think it's overworking or at any risk of burning out....it just sounds weird for those final few seconds. There's plenty of water in the tank, and no leaks. Have checked all the pipework forensically, and it never cuts in without a tap open so am confident about this. It's only in the few seconds before it cuts out that it sounds weird, so assume it must be something to do with the pressure cut off mechanisms. Ultimately it still works fine so am inclined to keep using it. It's always isolated when I'm not on the boat so would know straight away if it got worse or was cutting in/out when it shouldn't be. I wondered if anyone had had similar experiences, or would suggest doing anything beyond waiting for it to fail and then installing a new one. Thanks in advance!!

Perfect, thank you! Exactly what I was hoping the answer would be. Thought that was the case but really reassuring to have it confirmed.

My water pump (flojet R4405144A) recently developed a leak. It's been perfect for the 3 years I've had the boat and I imagine a long time before that too so decided to replace with the same model. When it arrived it had a very specific warning on the box that is has a bypass valve and shouldn't be used with an accumulator tank. My system does have an accumulator and i'd like to keep it if I can (no need for the pump to kick in if using water in the night etc). Even if the pump works well without an accumulator, I struggle to see how having one would be an issue, but wanted to sense check this first. I suspect my old pump had the bypass valve too and it isn't an issue(although this may have been added in the more recent versions of the same model). Before I installed it I wondered if anyone knew the logic or what kind of issues leaving the pressurised accumulator could cause theoretically? Thanks in advance!

Amazing, thank you

Gotcha. Is it ok to bring the gas bottle back into the locker in the meantime if touch dry, or is weight on it an issue with fully drying?

Yes the boat is in the water. Ok, What's the rationale behind that out of interest? Everything I would be painting is still several inches above the waterline if that matters. Are you meaning its too cold to apply the hammerite, or that the vactan will need longer before being ready? Thanks.

Hi all. I've been scraping out my gas locker today, and have coated with vactan once the loose rust was removed. I had a tin of hammerite smooth left over from previous jobs which I was planning to use over the top, though now notice it specifically says it doesn't need rust converters, primers etc first. I assume just because it doesn't need an undercoat, it's not going to be an issue that I've coated with vactan first? But given I don't really know anything about paint though worth checking with more knowledagble people first. Thanks :)

Apologies, and thank you for pointing this out to me. I should have known already. Will never do this again.

Hi, Just wanted to update and thank you all for the advice. I think I'm sorted now. I drained off a bit of coolant, bled the skin tank and put a new pressure cap on the coolant tank this morning. I haven't moved yet, but ran it in gear (making sure there were no neighbours around to annoy first) for over half an hour while still tied to the bank this morning, and all running perfectly without a hint of any of the previous issues. This is more than the amount of cruising time that was causing me issues before, and constantly in gear rather than idling through locks etc so I think I'm all good. Thank you very much for the tips and advice!

Sorry, the manifold is bowman.

Thank you - Not at all confident that it's the cap no - but all up for trying some cheap/easy fixes in the first instance. Realise I may have to go down a more expensive route afterwards. How did you know that it was that gasket that had failed before deciding to cut it off?

Thank you Alan will get one ordered. Hadn't realised there was a short/long neck distinction either. Thanks for pointing that out as I likely would have got it wrong!

Good point. Realise I've actually done this before and completely forgotten about that bit. I definitely have a bleed screw.

Looking around online I'm struggling to find anything below 7psi. Would this be close enough to be good enough as far as not splitting the rubber goes. Don't want to cause more problems for myself. Or any ideas where I could source a 5 psi? Thanks. Thanks, will be my next thing to look into if the cap doesn't sort it then. If it was air in the skin tank I assume this could be sorted by loosening the connection on one of the skin tank pipes and running the engine for a bit before tightening back up? Hopefully not loosing too much coolant into the engine bay in the process....

Thanks. Yes exhaust manifold with rubber end cap. Will order a 5 psi cap then. I assume if this does turn out to be any different to what it had on it before there's no harm to be done by having too low pressure? Thank you, will do all of this and report back when I next take the boat for a cruise.

Ok thanks, can try that. When you say until hot, will it be sufficient to try in situe or will it need to be engaged in gear for that to happen? As a slight aside. Was looking into sourcing a new cap too. The current one I have says ARH 1559 on it and I have no idea what this means. I was expecting to see a psi rating. Any tips on what I should be looking for if I replace?

Ah yes, I hadn't clocked that the previous posts were only talking about liquid. There is definitely a small amount of steam coming off too. Interested to hear if anyone had any further thoughts on diagnostic checks I could carry out. If you wouldn't expect steam even with the pressure cap removed then I assume replacing the cap isn't going to solve the problem either......

Thanks. Not very recently no. I flushed out the whole skin tank and put new water/antifreeze in within the last year, but would be very surprised if it'd been doing this for 8 months+ without me noticing, that said it's not impossible. Drove for another half hour this afternoon and had the same problem so the tiny leak wasn't the issue. I don't need to move for another 2 weeks now, and my solar setup is sufficient that I don't really need the engine for electricity. So I think my plan may be to source a new cap within the next fortnight. Potentially also siphon out a little of the coolant to take it down maybe an inch in the tank rather than wait to see if it eventually chucks enough out. If I still have the same issue when I next move after both those things I'll give it some more thought. Bee, although your message is somewhat reassuring and I would love to just ignore it. I know for sure that this never used to happen, and the fact that the engine is running hotter or in someway differently to how it did before makes me a bit uncomfortable. Although I know a bit, I'm very much only an enthusiastic amateur, so forgetting about the fact that something different is happening makes me very nervous that I may be doing further internal damage somehow. Though nobody actually seems to be suggesting that this is the case which is a relief! Thanks again.

Yes all standard as far as I'm aware. Provided it's not sorted and replacing the cap is my next step, will make sure I replace like with like. Thank you for pointing that out, that wasn't something I'd given thought to.