Kalapattar Posted April 6, 2021 Report Share Posted April 6, 2021 (edited) Hi! I’m looking to buy a new LPG gas water heater because flow is slow to the shower to provide hot temperatures! Heater always sounds like there’s not enough water! My pressure tank is about 3 bar Which is the best heater for flow rate on a narrow boat please? Is it the case of ‘the bigger the better? Ta! Edited April 6, 2021 by Kalapattar Link to comment Share on other sites More sharing options...
matty40s Posted April 6, 2021 Report Share Posted April 6, 2021 You need to increase ingoing water pipe size and water pump pressure, not buy a new water heater. New higher volume water pump might be needed. Ingoing piping should be 22mm, outgoing 15mm.... Link to comment Share on other sites More sharing options...
Kalapattar Posted April 6, 2021 Author Report Share Posted April 6, 2021 Hi! Thanks for your reply! Copper Pipe going to heater is 15mm since new! The heater is 6 ltrs. ta! Hi! The water pump is a jabsco shower/ drain one! Do you recommend a ‘Gulper’? Link to comment Share on other sites More sharing options...
matty40s Posted April 6, 2021 Report Share Posted April 6, 2021 What is the water heater?....having the same ingoing as outgoing pipe size for the water in a gas boiler will not give you what you want at the shower head. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 6, 2021 Author Report Share Posted April 6, 2021 (edited) Hi! The water pump is a jabsco shower/ drain one! Do you recommend a ‘Gulper? The heater is a Morco 6 ltr Ecoplus model Hi thanks for your advice on pipe size Edited April 6, 2021 by Kalapattar Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 7, 2021 Report Share Posted April 7, 2021 Look at the label on the domestic water pump and tell us what it says apart from just "Jabsco". It should have a model name like "Parmax" plus some numbers followed by lpm or gpm and another with bar after it. That will give us the designed cut out pressure and the flow rate. Thatw ill let us assess if it a pump pressure or flow rate problem. Only an idiot would try to use a shower DRAIN pump (the Gulper) as a domestic water pump because it has no pressure switch on it and it produces pulses of water so I am not sure that you have a clear idea about what does what in your system. Where is this water pump you refer to located in the boat? That will give us a clue to it being the domestic water pump or the shower drain pump (with a bit of luck). Link to comment Share on other sites More sharing options...
Richard10002 Posted April 7, 2021 Report Share Posted April 7, 2021 When I had a similar issue with my Rinnai instant gas water heater I got a variety of advice here and tried the simplest and most logical, (to me), first. This was to increase the pressure/power/flow, (call it what you will), from the pump. On my Jabsco pump, there is a screw under a blue plastic cover on the end of the pump which adjusts the pressure. I turned it in half turns both ways to identify which way increased the pressure, (can’t remember ), and increased it until the Rinnai turned on. It can’t have taken more than 2 or 3 half turns as there would have come a point where I would have decided it wasn’t working. The full make and model of the OPs pump would be good to know. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 7, 2021 Author Report Share Posted April 7, 2021 Ok, thanks for your reply and advice! Link to comment Share on other sites More sharing options...
Ex Brummie Posted April 9, 2021 Report Share Posted April 9, 2021 The Morco 6 litre is designed to give a temperature lift of 25oC at the highest water flow (5.7 lts per min) or 50oC at the lowest flow (2.7 lts per min) so at full flow if your incoming water is 5oC, you'll only get water at 30oC. At 5oC incoming water you would probably get about 3.5 lts per min. If your water pump only gives you 10 lts per min, all the tweaking of the pressure switch will make no difference to the amount pumped. The heater needs a minimum pressure of 1 bar (15 psi) to operate the diaphragm. 15mm pipework is more than adequate for the performance of the heater, Most boat pumps will give you about 25 -30 psi at least, so well within the scope of the heater specs. As has already been said, a Whale Gulper is totally the wrong type of pump for water supply. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 9, 2021 Author Report Share Posted April 9, 2021 Ok, thanks for your reply and advice! Link to comment Share on other sites More sharing options...
Detling Posted April 9, 2021 Report Share Posted April 9, 2021 Could it be lime scale build up? Most canal water points give very hard water. Link to comment Share on other sites More sharing options...
blackrose Posted April 9, 2021 Report Share Posted April 9, 2021 On 06/04/2021 at 22:07, Kalapattar said: Hi! The water pump is a jabsco shower/ drain one! Do you recommend a ‘Gulper? As the name suggests, your shower drain pump drains the shower and pumps the waste water out of the boat. It has absolutely nothing to do with the pressurised water going to your water heater. As Tony said, you need to look at your domestic/freshwater pump and either see if you can increase the pressure (and adjust any accumulator tank) or buy a new higher pressure pump. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 10, 2021 Author Report Share Posted April 10, 2021 Hi! I’m buying a pressurised pump and see how it goes from there. Ta! Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 10, 2021 Report Share Posted April 10, 2021 (edited) 6 hours ago, Kalapattar said: Hi! I’m buying a pressurised pump and see how it goes from there. Ta! What is a "pressurised pump"? The words Blackrose were "higher pressure pump". The pump pressurises the water in the system. In the light of the advice Ex Brummie gave it may be an idea for you to get one with a higher output (litres or gallons per minute). See this topic about reading the pump specifications. Edited April 10, 2021 by Tony Brooks Link to comment Share on other sites More sharing options...
TheBiscuits Posted April 10, 2021 Report Share Posted April 10, 2021 11 hours ago, Detling said: Could it be lime scale build up? Most canal water points give very hard water. Do they have a different supply then? I'd have thought they provide the same water as every other tap in each area ... 1 Link to comment Share on other sites More sharing options...
blackrose Posted April 10, 2021 Report Share Posted April 10, 2021 7 hours ago, Kalapattar said: Hi! I’m buying a pressurised pump and see how it goes from there. Ta! Yes just buy any old "pressurised pump" and see how it goes. If it's the wrong pump then it's fine, you'll only have wasted 100 quid or so. Or here's another idea: You could actually try to understand and follow the free advice given by experienced people on this forum. Your choice... Link to comment Share on other sites More sharing options...
Kalapattar Posted April 10, 2021 Author Report Share Posted April 10, 2021 Yes, advice is to buy a Parmax 2.9 Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 10, 2021 Report Share Posted April 10, 2021 1 hour ago, Kalapattar said: Yes, advice is to buy a Parmax 2.9 I don't recall seeing a Parmax 2.9 mentioned by name and that's after scanning the whole topic again. The 2.9 (as you don't give any units/suffixes could be gallons per minute or bar (pressure) and from what I can see you have been advised that you may need to increase both cut out pressure and out put volume so unless you tell us the full specification for this pump you may still not solve the problem and maybe waste close to £100, still it's your choice. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 10, 2021 Author Report Share Posted April 10, 2021 6 minutes ago, Tony Brooks said: I don't recall seeing a Parmax 2.9 mentioned by name and that's after scanning the whole topic again. The 2.9 (as you don't give any units/suffixes could be gallons per minute or bar (pressure) and from what I can see you have been advised that you may need to increase both cut out pressure and out put volume so unless you tell us the full specification for this pump you may still not solve the problem and maybe waste close to £100, still it's your choice. Hi! The pump is 11 ltrs per minute and cuts out at 2.7bar Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 10, 2021 Report Share Posted April 10, 2021 Just now, Kalapattar said: Hi! The pump is 11 ltrs per minute and cuts out at 2.7bar And the data from the old pump? It w uld seem from Ex Brummie's comments your new pump should be fine though. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 10, 2021 Author Report Share Posted April 10, 2021 Old pump is a drain pump so not suitable anyway! I do have an accumulator tank, and advert states they’re not required Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 10, 2021 Report Share Posted April 10, 2021 1 minute ago, Kalapattar said: Old pump is a drain pump so not suitable anyway! I do have an accumulator tank, and advert states they’re not required FWIW I have seen pumps that are marketed as shower drain pumps that seem to have exactly the same internals as a normal domestic water pump. That is multiple pumping chambers and valves. One of this type probably would do the job proving it could reach the pressure. If it were a Gulper (single large diaphragm and two large valves) I can imagine the flame going up and down with each gulp. 1 Link to comment Share on other sites More sharing options...
Kalapattar Posted April 10, 2021 Author Report Share Posted April 10, 2021 Ok thanks for all your advice! Link to comment Share on other sites More sharing options...
Ex Brummie Posted April 13, 2021 Report Share Posted April 13, 2021 On 10/04/2021 at 12:00, Kalapattar said: Old pump is a drain pump so not suitable anyway! I do have an accumulator tank, and advert states they’re not required Only just come back to this post. Whatever you do, do not ditch the accumulator. If you do, you will burn out the pressure switch in no time, especialyy if using the Morco at a reduced rate to get hot water. Link to comment Share on other sites More sharing options...
Kalapattar Posted April 13, 2021 Author Report Share Posted April 13, 2021 Ok thanks! Link to comment Share on other sites More sharing options...
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