Your expertise is required - vid inside

[Big Rigg]

Ahoy matey!

 

 

I hope you can help me figure out what is wrong with this cursed water pump.

The boiler works well enough on a low setting but as I raise the settings, it disrupts the flow of the water. As a result, the water comes out cold to warmish in the shower.

As they say, a picture is worth a thousand words, so here are 2 videos:

Kitchen sink:

https://www.youtube.com/watch?v=NE-ZC6j4zLE

Shower:

https://www.youtube.com/results?search_query=faulty+narrowboat+pump

 

You can see in the second video that it gets much worse in the shower.

 

 

[Jess--]

I think you need a pressure reservoir on your water system (I forget the proper name).

 

what I would guess is happening is that your boiler is taking water slowly enough for your pump to get up to pressure and shut down, then you have a delay while the pressure drops again and the pump restarts (the reservoir smooths this out to give fairly constant pressure)

[Arthur Marshall]

The boiler, if it's an instant water heater like mine, raises the temperature of the water flow by restricting the water going through the system. Trouble with mine is that as my water tank is below the waterline, in winter the water is very cold indeed, and if you then turn the flow down to get hotter water, the boiler overheats and turns the flame out.

It gets worse in mine if the water flow is restricted in the first place by rust or clogging where the pipe comes from the tank - maybe you need a bigger pump to shove more water through the system?

[Big Rigg]

re you thinking of an accumulator?

 

I think you need a pressure reservoir on your water system (I forget the proper name).

 

what I would guess is happening is that your boiler is taking water slowly enough for your pump to get up to pressure and shut down, then you have a delay while the pressure drops again and the pump restarts (the reservoir smooths this out to give fairly constant pressure)

I have googled "pressure reservoir"and all I got was accumulator, is this it?

If it is, mine is brand new, installed in December

[Guest]

I think you need a pressure reservoir on your water system (I forget the proper name).

 

what I would guess is happening is that your boiler is taking water slowly enough for your pump to get up to pressure and shut down, then you have a delay while the pressure drops again and the pump restarts (the reservoir smooths this out to give fairly constant pressure)

 

Accumulator,

[Chewbacka]

hI would Have a look at the spec sheet for the gas heater and see if the output from the pump meets the min flow and pressure required.

[Jess--]

re you thinking of an accumulator?

 

I have googled "pressure reservoir"and all I got was accumulator, is this it?

If it is, mine is brand new, installed in December

that's the one, my mind went to a total blank when I tried to think of what it was called.

 

I would suggest checking the air pressure side of it as too high a pressure or too low a pressure can make it ineffective and cause the surging effect that you can see at the tap.

 

can you confirm that your pump is starting and stopping in time with the surges?

[Iain_S]

Does the water temperature vary as well?

 

As others have said, turning up the temp. at the heater restricts water flow, which causes the pump to cycle. A correctly set (just below pump cut in pressure) accumulator will help a lot, but another trick I found a few years ago with a similar problem was to turn a cold tap on, just enough to keep the pump running continously.

[matty40s]

It looks like you only have a 15mm water supply to the boiler, this should be larger - 22mm and preferably a separate supply to the shower cold mixer feed, your gas pipe also seems to be a very small size.

Edited January 10, 2016 by matty40s

[Big Rigg]

that's the one, my mind went to a total blank when I tried to think of what it was called.

 

I would suggest checking the air pressure side of it as too high a pressure or too low a pressure can make it ineffective and cause the surging effect that you can see at the tap.

 

can you confirm that your pump is starting and stopping in time with the surges?

The pump starts and stops with the surges.

 

I had a professional who charged me over a £1000 to install the hot water (boiler+ accumulator and a couple of other things). Now, he doesn't reply to my emails/texts/phone calls.

It looks like you only have a 15mm water supply to the boiler, this should be larger - 22mm and preferably a separate supply to the shower cold mixer feed, your gas pipe also seems to be a very small size.

As I said in my previous post, I just had the work done by a technician recommended by a marina. He lives there I think. I haven't heard a reply from him since before Christmas.

[nicknorman]

It looks like you have an accumulator, but it isn't pressurised correctly. Effectively it isn't doing anything, as can be seen by the very rapid pump switching.

 

It looks like the accumulator is the blue thing near the pump. It should have an air valve on top (like a car tyre valve), probably covered with some sort of flat cap that can be unscrewed. If the air pressure is much too high, or much too low, it will not work.

 

To set it you will need something like a car tyre foot pump with a pressure gauge. First, switch off the pump and open all the taps to depressurise the system. Then attach the foot pump to the accumulator valve and pump up to about 15psi. Disconnect the foot pump, close taps, turn on the pump and try the shower again. Hopefully the pump will no longer cycle rapidly and the burner on the heater will stay lit.

 

The optimum pressure may be a little over 15psi but try that to start with anyway.

[ditchcrawler]

Ahoy matey!

 

 

I hope you can help me figure out what is wrong with this cursed water pump.

The boiler works well enough on a low setting but as I raise the settings, it disrupts the flow of the water. As a result, the water comes out cold to warmish in the shower.

As they say, a picture is worth a thousand words, so here are 2 videos:

Kitchen sink:

https://www.youtube.com/watch?v=NE-ZC6j4zLE

Shower:

https://www.youtube.com/results?search_query=faulty+narrowboat+pump

 

You can see in the second video that it gets much worse in the shower.

 

 

What happens when when you just draw off cold water?

[peterboat]

It looks like you have an accumulator, but it isn't pressurised correctly. Effectively it isn't doing anything, as can be seen by the very rapid pump switching.

 

It looks like the accumulator is the blue thing near the pump. It should have an air valve on top (like a car tyre valve), probably covered with some sort of flat cap that can be unscrewed. If the air pressure is much too high, or much too low, it will not work.

 

To set it you will need something like a car tyre foot pump with a pressure gauge. First, switch off the pump and open all the taps to depressurise the system. Then attach the foot pump to the accumulator valve and pump up to about 15psi. Disconnect the foot pump, close taps, turn on the pump and try the shower again. Hopefully the pump will no longer cycle rapidly and the burner on the heater will stay lit.

 

The optimum pressure may be a little over 15psi but try that to start with anyway.

some do come set at 3.5 bars ask me how i know

[Ex Brummie]

Potable water expansion vessels/accumulators are generally set to 3.5 bar, or approx. 50 psi. What pressure is your pump set at? If around 28 psi, you need to reduce the pressure in the vessel to around 15 psi. This will smooth out the supply pressure from your pump that is caused by the differential range of the pressure switch. If running a shower through a multi point, you may find, with a correctly adjusted vessel, that the pump runs for 10 -15 secs, switches for 10 -15 secs, then off again. This is better for the pump than the pulsing caused by low flow through the system.

[Big Rigg]

It looks like you have an accumulator, but it isn't pressurised correctly. Effectively it isn't doing anything, as can be seen by the very rapid pump switching.

 

It looks like the accumulator is the blue thing near the pump. It should have an air valve on top (like a car tyre valve), probably covered with some sort of flat cap that can be unscrewed. If the air pressure is much too high, or much too low, it will not work.

 

To set it you will need something like a car tyre foot pump with a pressure gauge. First, switch off the pump and open all the taps to depressurise the system. Then attach the foot pump to the accumulator valve and pump up to about 15psi. Disconnect the foot pump, close taps, turn on the pump and try the shower again. Hopefully the pump will no longer cycle rapidly and the burner on the heater will stay lit.

 

The optimum pressure may be a little over 15psi but try that to start with anyway.

Sound advice, I'll get on it, fingers crossed

What happens when when you just draw off cold water?

No real issue with the cold water

some do come set at 3.5 bars ask me how i know

How do you know?

Potable water expansion vessels/accumulators are generally set to 3.5 bar, or approx. 50 psi. What pressure is your pump set at? If around 28 psi, you need to reduce the pressure in the vessel to around 15 psi. This will smooth out the supply pressure from your pump that is caused by the differential range of the pressure switch. If running a shower through a multi point, you may find, with a correctly adjusted vessel, that the pump runs for 10 -15 secs, switches for 10 -15 secs, then off again. This is better for the pump than the pulsing caused by low flow through the system.

I was not aware of any of this before I made this thread. Guess I'll have to gear up.

 

 

Am I the only one to think the technician is completely out of order?

[nicknorman]

 

Am I the only one to think the technician is completely out of order?

No, however it's not that unusual I'm afraid. There are lots of incompetent cowboys out there. I'm afraid pretty much the only answer is to learn to sort these things out yourself. Which of course you are doing!

[Big Rigg]

No, however it's not that unusual I'm afraid. There are lots of incompetent cowboys out there. I'm afraid pretty much the only answer is to learn to sort these things out yourself. Which of course you are doing!

I called a Marina nearby and they recommended me this guy, who lives there. The marina are now telling me there's nothing they can do but pass on the message to him. I'm fuming.

[nicknorman]

I called a Marina nearby and they recommended me this guy, who lives there. The marina are now telling me there's nothing they can do but pass on the message to him. I'm fuming.

 

So you have money, you employ a professional, you expect a job well done. WRONG! in my experience anyway. If you want a job doing well you have to do it yourself or at least have a good handle on what is being done. Sorry, nobody said life was easy!

 

Anyway I suspect adjusting the pressure of the accumulator will sort it, so if that's the only problem it is only a big deal in principle, not in practice. Clearly the guy didn't test / commission the installation properly, he was probably rushing to get to the next job. I suppose the only thing to consider is whether he was equally shoddy with the gas / boiler installation, which has the potential to be more serious than just cold showers.

 

Did you check if he was gas safe registered with a ticket for working on boat LPG systems?

[Ex Brummie]

I know about potable water expansion vessels(white or blue) because I have bought many of them, and they are generally installed on mains pressure hot water systems. Normal heating expansion vessels ( the red ones) are generally precharged to 1 bar.

Marine water pumps these days are sold as not needing an accumulator, which if hot water is provided by a calorifier, is probably OK. The OP has said that there is no problem with the cold water. This is because the pump has an unobstructed outlet. A multipoint will only pass around 6 lts/min at best, less if you want it hotter at present. The pump overprovides this amount and will pulse. The other problem that having no accumulator will possibly cause, is the lack of controllability with any mixer tap. If this is encountered, then it can be rectified by the addition of an isolating valve on the cold supply before the valve, and throttle it down to the same level, or maybe a little less than the throughput of the heater.

I would be annoyed with this installer, and would feel he deserves some flak.

[Big Rigg]

So you have money, you employ a professional, you expect a job well done. WRONG! in my experience anyway. If you want a job doing well you have to do it yourself or at least have a good handle on what is being done. Sorry, nobody said life was easy!

 

Anyway I suspect adjusting the pressure of the accumulator will sort it, so if that's the only problem it is only a big deal in principle, not in practice. Clearly the guy didn't test / commission the installation properly, he was probably rushing to get to the next job. I suppose the only thing to consider is whether he was equally shoddy with the gas / boiler installation, which has the potential to be more serious than just cold showers.

 

Did you check if he was gas safe registered with a ticket for working on boat LPG systems?

 

He is meant to be gas safe registered. I didn't check personally. I trusted the Marina.

[nicknorman]

He is meant to be gas safe registered. I didn't check personally. I trusted the Marina.

It's just that as I understand it (and I'm not an expert on gas) there is more to it than just "gas safe", there are different authorisations within that umbrella and there is a specific one either for boats and/or LPG (can't remember exactly).

 

Anyway, sorry if this is going to sound harsh but it is a case of caveat emptor. If you take others' word for such things eventually you will get stung. In this case of course we don't actually know if he was properly qualified or not, and even then having a bit of paper with a qualification on it doesn't necessarily mean one is any good! I'm a trusting soul, as you can tell ... NOT!

[ditchcrawler]

 

No real issue with the cold water

 

This makes me doubt problems with the accumulator but I know nothing about gas heaters

[nicknorman]

This makes me doubt problems with the accumulator but I know nothing about gas heaters

I think it's to do with the flow rate. With a cold tap well on, the flow rate is high and the pump is on full time, not cycling. But with the hot water, the flow rate is necessarily throttled by the boiler (since a fast flow would result in cool water) and the pump starts cycling. You can hear it in the shower vid, cycling very fast which means that there is effectively no accumulator.

[ditchcrawler]

I think it's to do with the flow rate. With a cold tap well on, the flow rate is high and the pump is on full time, not cycling. But with the hot water, the flow rate is necessarily throttled by the boiler (since a fast flow would result in cool water) and the pump starts cycling. You can hear it in the shower vid, cycling very fast which means that there is effectively no accumulator.

Could well be right, as I said I know nowt about gas heaters

[Lowcliff]

Name and shame the installer, this might prevent other people from having the same problem.