Water pump woes

[WotEver]

16 hours ago, Poppin said:

the prefilter before the kitchen sink is reducing water pressure a bit too much,

[pedant] No, it’s reducing the flow rate [/pedant]. 

Try removing the pre-filter. Assuming that you have a filter between the tank and the pump there’s nothing for a tap pre-filter to, er, filter. 

[Guest]

Bringing up an old(ish) topic as I’ve been having a few minor water pump issues myself. So the problem I’ve currently got is I’ve got a Morco water heater in the bathroom. It seems to work without a problem with the hot water tap in the kitchen however, in the shower although I feel like I’ve got enough water pressure as the water comes out reasonably strong, it sort of pulsates out of the shower head (and it’s a pretty basic shower head) - as a result the Morco water heater keeps turning on and off and it doesn’t really get up to temperature very easily.

 

What I’ve found is if I put the shower head low down in the shower, it does kick into action but as soon as you lift the shower head up then it stops activating the Morco and kills the heater.

 

I’m guessing this is a problem with the water pressure - the water pump is a 20psi Shureflo model (I forget which one it is exactly). It’s certainly not as if there is much of a water pressure problem because it does come out of the taps in the bathroom and kitchen fine. I feel like this pulsating affair has only recently started but maybe I just haven’t noticed it. The Morco water heater seems to work really well with the kitchen tap, I will have to test it with the bathroom sink tap but certainly the shower in the bathroom is a problem.

 

What I’ve just tried doing is turning off the water pump, opening all the taps to let any pressure/air out and then I pumped some air into the accumulator tank. Didn’t seem to make much difference.

 

Any other thoughts of what I could try? Thanks all!

[Alan de Enfield]

11 minutes ago, NB Caelmiri said:

Any other thoughts of what I could try? Thanks all!

 

I have sent you a PM.

[Chewbacka]

5 minutes ago, Alan de Enfield said:

 

I have sent you a PM.

Do you have a secret spell for fixing water pumps??

 

[Alan de Enfield]

1 minute ago, Chewbacka said:

Do you have a secret spell for fixing water pumps??

 

No, just a message.

[Jen-in-Wellies]

13 hours ago, NB Caelmiri said:

Bringing up an old(ish) topic as I’ve been having a few minor water pump issues myself. So the problem I’ve currently got is I’ve got a Morco water heater in the bathroom. It seems to work without a problem with the hot water tap in the kitchen however, in the shower although I feel like I’ve got enough water pressure as the water comes out reasonably strong, it sort of pulsates out of the shower head (and it’s a pretty basic shower head) - as a result the Morco water heater keeps turning on and off and it doesn’t really get up to temperature very easily.

 

What I’ve found is if I put the shower head low down in the shower, it does kick into action but as soon as you lift the shower head up then it stops activating the Morco and kills the heater.

 

I’m guessing this is a problem with the water pressure - the water pump is a 20psi Shureflo model (I forget which one it is exactly). It’s certainly not as if there is much of a water pressure problem because it does come out of the taps in the bathroom and kitchen fine. I feel like this pulsating affair has only recently started but maybe I just haven’t noticed it. The Morco water heater seems to work really well with the kitchen tap, I will have to test it with the bathroom sink tap but certainly the shower in the bathroom is a problem.

 

What I’ve just tried doing is turning off the water pump, opening all the taps to let any pressure/air out and then I pumped some air into the accumulator tank. Didn’t seem to make much difference.

 

Any other thoughts of what I could try? Thanks all!

AI don't have a Morco gas heater, so no direct experience, but here are my thoughts.

 

What is the specified flow rate of the pump? If the flow rate is low, then the pressure will drop. What size pipes are between the pump, Morco and shower? If they are small diameter then, again, flow rate will be low and the pressure will drop away, leading to the Morco getting in to a tizz and shutting down. Lots of 90 degree angles in the pipework have a similar effect. Easiest to try would be a higher flow rate pump, though at a cost. Changing the pipework size, say 15 to 22mm, would be more difficult and messy, depending on your boat fit out.

 

My boat has 15mm OD Speedfit pipe throughout. The pump is around 20' from the water tank. I recently fitted a water flow meter to the pump input as part of a project to build a water tank level meter. This showed that the actual water flow rate, with the pump on and all hot and cold taps open, was actually around half what was written on the pump label. Not a problem for me as I don't have a Morco gas heater, or anything else that is sensitive to flow rate and pressure in the same way, but goes to show the effect of the pump trying to force water through a narrow bore pipe on the rate. The pressure in the pipe drops rapidly away from the pump with the water flowing through the 15mm pipes. With existing pipes, moving the pump closer to the Morco might work as the local pressure should be higher.

 

Jen

[Chewbacka]

If it is pulsing it is probably causing the pump to cycle, try removing the shower head and let water flow from the open pipe.  If it’s now ok you need a shower head with bigger holes.  Maybe you have one of those water saving shower heads that don’t let much water out.  Anyway, just a thought.

[Guest]

14 minutes ago, Chewbacka said:

If it is pulsing it is probably causing the pump to cycle, try removing the shower head and let water flow from the open pipe.  If it’s now ok you need a shower head with bigger holes.  Maybe you have one of those water saving shower heads that don’t let much water out.  Anyway, just a thought.

I shall give that a go. I'm pretty sure that it never used to do this. I'll have to double check the other taps in the boat - kitchen sink and bathroom sink and see if they're remotely pulsating. I've got both the Morco and a calorifier and was using the hot water from the calorifier this morning, it was definitely pulsating. I'll start with the shower head and go from there! Thanks for the suggestion!

[Ex Brummie]

Are you mixing cold water with the hot to your shower? If so, this will directly the flow to the Morco and cause the problems you have with a low performance punp .

 

Posted before your last reply. Depending how you control the supply to the Morco/calorifier it will havean effect on performance. Feeding aMorco with hot water is not very clever

Edited August 10, 2019 by Ex Brummie

[Guest]

27 minutes ago, Jen-in-Wellies said:

AI don't have a Morco gas heater, so no direct experience, but here are my thoughts.

 

What is the specified flow rate of the pump? If the flow rate is low, then the pressure will drop. What size pipes are between the pump, Morco and shower? If they are small diameter then, again, flow rate will be low and the pressure will drop away, leading to the Morco getting in to a tizz and shutting down. Lots of 90 degree angles in the pipework have a similar effect. Easiest to try would be a higher flow rate pump, though at a cost. Changing the pipework size, say 15 to 22mm, would be more difficult and messy, depending on your boat fit out.

 

My boat has 15mm OD Speedfit pipe throughout. The pump is around 20' from the water tank. I recently fitted a water flow meter to the pump input as part of a project to build a water tank level meter. This showed that the actual water flow rate, with the pump on and all hot and cold taps open, was actually around half what was written on the pump label. Not a problem for me as I don't have a Morco gas heater, or anything else that is sensitive to flow rate and pressure in the same way, but goes to show the effect of the pump trying to force water through a narrow bore pipe on the rate. The pressure in the pipe drops rapidly away from the pump with the water flowing through the 15mm pipes. With existing pipes, moving the pump closer to the Morco might work as the local pressure should be higher.

 

Jen

I'll check the flow rate but 7l/m seems to be familiar although that might be from the other Shurflo pumps I was looking at. Pipes are all 15mm. I'm pretty sure this never used to happen so it could be that the pump or accumulator are on their way out. I think I'll try Chewy's suggestion first, double check the kitchen/bathroom taps and go from there.

 

Thanks!

1 minute ago, Ex Brummie said:

Are you mixing cold water with the hot to your shower? If so, this will directly the flow to the Morco and cause the problems you have with a low performance punp .

Only mixing cold/hot water at the shower mixer tap, not before.

[Ex Brummie]

2 minutes ago, NB Caelmiri said:

 

Only mixing cold/hot water at the shower mixer tap, not before.

The cold feed will reduce the hot feed pressure/volume into the Morco.

[Guest]

3 minutes ago, Ex Brummie said:

The cold feed will reduce the hot feed pressure/volume into the Morco.

Ah right, I'm with you. I'll check that out too and see how it is on full hot.

Edited August 10, 2019 by NB Caelmiri

[Guest]

On 01/12/2018 at 11:15, Tony Brooks said:

 

I don't understand where this "not charging the calorifier" comes from. If you have 25 psi pressure then that pressure will force water into the calorifier (with the hot taps open) and air out of the taps. If it does not and the calorifier remains empty then there must be something blocking the flow - either into the pump or between pump - calorifier - open taps.

 

The noise make me suspect its on the inlet side of the pump and that will also cause a poor flow.

 

Although flow from an outlet will be proportional to pressure the more important data is the delivery rate of the pump (litres per min).  Have you given us the flow rate of the old pump? Its not in the above. If the new pump output (l/m) is more than the old one then you are looking at undersized pipes for the run length or a physical deliberate or accidental blockage.

That happened to mine a few weeks ago. The filter to pump inlet was full of gunge. Blew it out and normal service resumed. The Jabsco pump has also gradullay got quieter again.

[WotEver]

3 hours ago, NB Caelmiri said:

I'm pretty sure that it never used to do this.

Have you checked the shower head for limescale?  A soaking in Cilit Bang might assist. 

[Guest]

So this gets curiouser. Removed the shower head and ran the hot water - it was pulsating out of the shower hose with or without the shower head attached so that's not it. I've then checked the other taps and it's doing the same but only for the hot water side. The cold water side is fine. It appears to do this when running through either my calorifier or the Morco. In the bathroom I have a lever that lets you pick there the hot water source is coming from. Also when I'm running the hot water, I can hear the water pump pulsating/switching on and off. This pulsating occurs both from either hot water source and it is happening on all taps (and only on the hot tap). Now I think about it, I have a feeling it has always done this but perhaps not as much as it is doing now.

[Tony Brooks]

6 minutes ago, NB Caelmiri said:

So this gets curiouser. Removed the shower head and ran the hot water - it was pulsating out of the shower hose with or without the shower head attached so that's not it. I've then checked the other taps and it's doing the same but only for the hot water side. The cold water side is fine. It appears to do this when running through either my calorifier or the Morco. In the bathroom I have a lever that lets you pick there the hot water source is coming from. Also when I'm running the hot water, I can hear the water pump pulsating/switching on and off. This pulsating occurs both from either hot water source and it is happening on all taps (and only on the hot tap). Now I think about it, I have a feeling it has always done this but perhaps not as much as it is doing now.

 

Domestic water pumps cycle (pulse) when the flow out of the system is less than the volume of flow from the pump. That's it. End of. An accumulator will not stop the cycling although it will extend the cycling period so maybe you won't notice t but you will do when the take a shower because water is drawn for longer. Anything that impede water flow may induce cycling and from the above it seems to me that you have long pipe runs for the hot water. This is fairly normal for a narrowboat but changing the main supply pipe to the calorifier and then to the hot taps for 22mm may help but I don't think it is worth it.

 

The question is how to solve the Morco issue, I don't see it as a problem with the calorifier because although I can give you at least two reasons cycling pumps are not a good idea the pumps seem to put up with it. Before doing anything more drastic take the shower hose off completely and check it does not have a strainer in it where is screws onto the mixer or whatever. Then make sure the plastic inner sleeve not kinking when the hose bends. I assume you have already descaled the shower head as alluded to above. I also assume that you have checked the accumulator pressure and ensured its set to about half the pump's cut out pressure.

 

Messing with the pump cut out pressure may be enough to alter the flow through the system enough to prevent cycling. On the standard pump system altering the cut out pressure alters the cut in pressure as well so try it both ways. You would stand more chance if you fitted a Square D 9D Square) pressure switch where you can alter the pressures independently.

 

Opening another tap a little when you are showering will waste water but will also increase the flow rate from the system so the pump can't cut out.

 

Most instant gas water heaters have a water temperature control and that seems to simply reduce the flow through the unit as you increase the water temperature and this induce pump cycling. Ideally you would set the shower temperature with that so you mix no cold water with the shower mixer but then you would get scalded when showering from the calorifier.

 

There are some water pumps that alter their speed to match demand, pone of those will not cycle but they cost. Others have a bypass valve inside them that opens just before the pre-set cut out pressure thereby preventing cycling (in theory) by venting some output back to the inlet. These also cost more than a standard pump.

 

My own personal view is mixed systems are overly complicated and  although convenient when tied up for a long time instant gas water heaters are more trouble than they are worth unless you have a direct raw water cooled engine or an air cooled one but that is just me. Others differ.

[Guest]

1 hour ago, Tony Brooks said:

 

Domestic water pumps cycle (pulse) when the flow out of the system is less than the volume of flow from the pump. That's it. End of. An accumulator will not stop the cycling although it will extend the cycling period so maybe you won't notice t but you will do when the take a shower because water is drawn for longer. Anything that impede water flow may induce cycling and from the above it seems to me that you have long pipe runs for the hot water. This is fairly normal for a narrowboat but changing the main supply pipe to the calorifier and then to the hot taps for 22mm may help but I don't think it is worth it.

 

The question is how to solve the Morco issue, I don't see it as a problem with the calorifier because although I can give you at least two reasons cycling pumps are not a good idea the pumps seem to put up with it. Before doing anything more drastic take the shower hose off completely and check it does not have a strainer in it where is screws onto the mixer or whatever. Then make sure the plastic inner sleeve not kinking when the hose bends. I assume you have already descaled the shower head as alluded to above. I also assume that you have checked the accumulator pressure and ensured its set to about half the pump's cut out pressure.

 

Messing with the pump cut out pressure may be enough to alter the flow through the system enough to prevent cycling. On the standard pump system altering the cut out pressure alters the cut in pressure as well so try it both ways. You would stand more chance if you fitted a Square D 9D Square) pressure switch where you can alter the pressures independently.

 

Opening another tap a little when you are showering will waste water but will also increase the flow rate from the system so the pump can't cut out.

 

Most instant gas water heaters have a water temperature control and that seems to simply reduce the flow through the unit as you increase the water temperature and this induce pump cycling. Ideally you would set the shower temperature with that so you mix no cold water with the shower mixer but then you would get scalded when showering from the calorifier.

 

There are some water pumps that alter their speed to match demand, pone of those will not cycle but they cost. Others have a bypass valve inside them that opens just before the pre-set cut out pressure thereby preventing cycling (in theory) by venting some output back to the inlet. These also cost more than a standard pump.

 

My own personal view is mixed systems are overly complicated and  although convenient when tied up for a long time instant gas water heaters are more trouble than they are worth unless you have a direct raw water cooled engine or an air cooled one but that is just me. Others differ.

Thanks Tony! Some very useful information there. I shall experiment with the heat settings on the boiler and see what gives with that and I'll have a look at the shower head again too. I only use the shower on weekends and very occasionally otherwise (the office I work from has a shower that I use in the morning) so it's definitely not the end of the world but it'd be good to get this sorted or at least improve the performance a bit! I'll try out some of your suggestions and see how I get on! Thanks again!

[George and Dragon]

On 10/08/2019 at 16:11, WotEver said:

Have you checked the shower head for limescale?  A soaking in Cilit Bang might assist. 

I just use vinegar.

But CB may be stronger so worth using if you don't have time to leave it overnight.