# water pump erratic



## buffallobill (Sep 28, 2007)

i have a small problem, if i run the cold water taps shower/sink or kitchen , 
the pump runs perfect, on /off brilliantly, if i run hot water the pump runs erratically, sounds like pulsing,then when i turn hot tap off the pulsing carries on for a further 10/20 seconds, i have tried adjusting the pressure on the small block with a thumb screw on top but no avail, seeing the cold water works on/off perfectly i am at a loss, has anyone any suggestions please. the water heater is a carver with electric or gas heater,on a swift sundance 590 rl. thanks bill. :?


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## Zebedee (Oct 3, 2007)

buffallobill said:


> i have a small problem, if i run the cold water taps shower/sink or kitchen ,
> the pump runs perfect, on /off brilliantly, if i run hot water the pump runs erratically, sounds like pulsing,then when i turn hot tap off the pulsing carries on for a further 10/20 seconds, i have tried adjusting the pressure on the small block with a thumb screw on top but no avail, seeing the cold water works on/off perfectly i am at a loss, has anyone any suggestions please. the water heater is a carver with electric or gas heater,on a swift sundance 590 rl. thanks bill. :?


Mine does almost the same Bill.

I asked the technician at our dealers, and he said they often sound as though they are at death's door, but not to worry as it depends where and how they are mounted.

The run-on with the hot water is just the pump pressurising that part of the system again, and re'filling the hot tank. They all doo it to a greater or lesser degree - mine certainly does.

Don't think you have a problem.

Cheers


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## Charisma (Apr 17, 2008)

buffallobill said:


> i have a small problem, if i run the cold water taps shower/sink or kitchen ,
> the pump runs perfect, on /off brilliantly, if i run hot water the pump runs erratically, sounds like pulsing,then when i turn hot tap off the pulsing carries on for a further 10/20 seconds, i have tried adjusting the pressure on the small block with a thumb screw on top but no avail, seeing the cold water works on/off perfectly i am at a loss, has anyone any suggestions please. the water heater is a carver with electric or gas heater,on a swift sundance 590 rl. thanks bill. :?


I fitted a Fiamma A20 expansion tank to the pump output pipe and it fixed this problem completely. The expansion tank stops all pump pulsing and keeps the water pressure constant. Brilliant device. Don't know why they are not fitted as standard.

See: http://www.fiamma.it/prodotti/prodotti.asp?Lingua=EN&Linea=03&Fam=P08


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## JohnsCrossMotorHomes (Jul 21, 2007)

Cooorect Zeb.

You got the answer in one!


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## buffallobill (Sep 28, 2007)

JohnsCrossMotorHomes said:


> Cooorect Zeb.
> 
> You got the answer in one!


thank you charisma and peter, is the fiamma a20 easy to fit.are there insalation instructions with it, does it come already pressurised, and finally what price do they cost, cheers and thanks again bill.


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## JohnsCrossMotorHomes (Jul 21, 2007)

buffallobill said:


> JohnsCrossMotorHomes said:
> 
> 
> > Cooorect Zeb.
> ...


Hi, yes easy to fit and price is £18.

Regards


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## buffallobill (Sep 28, 2007)

fiamma A20 expansion tank ordered , thanks charisma useful link .


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## buffallobill (Sep 28, 2007)

john cross motor homes , superb service , recieved expansion tank ,fiamma A20 yesterday will fit this weekend,


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## Alfa_Scud (Sep 27, 2006)

Same here for JohnsCross, ordered Monday, delivered yesterday, went to fit it then realised all my fittings are push fit, so it's off to find a couple of 1/2"-12mm fittings from the local plumbers merchant & try again tonight.


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## Alfa_Scud (Sep 27, 2006)

Just a follow on from this - I put the connector size on there, but am I correct? Can someone please just confirm that the cold water pipe size in my van is 12mm, or is it 15? Or, indeed is it 10? I should have looked at the collars on the existing fittings last night but just assumed it was 12.


Anyone? Anyone? Cheers


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## buffallobill (Sep 28, 2007)

Alfa_Scud said:


> Just a follow on from this - I put the connector size on there, but am I correct? Can someone please just confirm that the cold water pipe size in my van is 12mm, or is it 15? Or, indeed is it 10? I should have looked at the collars on the existing fittings last night but just assumed it was 12.
> 
> Anyone? Anyone? Cheers


now that is a thought i think mine are push fittings as well, will have to investigate, if you find out any info, could you please put it up on this reply. of what you had to use to convert from push fit ,


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## Alfa_Scud (Sep 27, 2006)

Well just been to the local plumbers merchant, as I thought it is 12mm pipe.

So sod's law being as it is you can't get a 1/2"-12mm, so it's either a 1/2"-3/8" bush then a 3/8"-12mm push fit (which is what I've done) or a 1/2"-15mm tap connector & a 15mm-12mm stem. I would have gone the second route but they'd no 15-12 stems!

Let's see what happens this evening now


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## Charisma (Apr 17, 2008)

buffallobill said:


> Alfa_Scud said:
> 
> 
> > Just a follow on from this - I put the connector size on there, but am I correct? Can someone please just confirm that the cold water pipe size in my van is 12mm, or is it 15? Or, indeed is it 10? I should have looked at the collars on the existing fittings last night but just assumed it was 12.
> ...


I can't be sure what size the pipe are but seem to remember they are 10mm. Anyway I contacted John Guest

http://www.johnguest.com/range_spec.asp?a=PLUMB

as they make the Speedfit fittings that Swift use (on my van anyway), and they put me intouch with a local supplier to me who had the fittngs I needed.

The reason I can't be sure, is that my van is at Swift having its floor replaced  and I can't go and check.

Hope that helps.

Dave


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## Charisma (Apr 17, 2008)

I have looked back my emails to John Guest. The actual parts you need are 2 x CM451214FS

http://www.johnguest.co.uk/part_spec.asp?s=CM45_D1

Customer services at John Guest should be able to give you a local supplier.

It is 12mm outside diameter pipe to 1/2" BSP thread. These replace the push on connectors supplied with the Fiamma A20 and you just have to cut the pipe from the pump outlet and push the ends in.

Nice and easy 

Dave


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## buffallobill (Sep 28, 2007)

thank you dave. much appreciated, will fit it this weekend,off to get the bits tommorrow .cheers bill.


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## buffallobill (Sep 28, 2007)

managed to obtain stem reducer 15mm -12mm, and 12mm equal straights, 2 of each, a piece of 15mm o/d 13mm i/d pipe, 

fitted the 15mm pipe onto expansion tank, used the piece of blue striped pipe 12mm, i cut off as a pipe insert , and connected this to the 15-12mm stem reducer,then push fit the 12mm equal straight onto it, then connected the original water pipe to the 12mm equal straight, and job is done, got the parts from READS caravans in blackburn, lancs.

i used the piece of blue striped water pipe i cut off as a pipe insert because the 15mm pipe was very flexible and thin walled first fit dicovered leak at the 15mm connection , the pipe insert strengthened the pipe wall and leak cured. very satisfied with the difference it has made, no more pulsing of the water pump. thanks guys for all the help, much appreciated, all the best bill.


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## Alfa_Scud (Sep 27, 2006)

*A20 accumulator*

Cheers Charisma for the JohnGuest part number, unfortunately I was too keen to have to wait so went with my original thought of bush then 12mm fitting, managed to get it fit OK, although space was a little tight so I fit it on the opposite side to the pump.
No problems though, all watertight & it works (or seems to!) very well.


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## Charisma (Apr 17, 2008)

Glad it seems to work. I think it should go on the output side of the pump though to maintain pressure at a constant level even after the pump turns off.

Not sure what affect it will have on the input side.

Dave


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## zappy61 (May 1, 2005)

*fiamma expansion tank*

I am thinking of fitting an expansion tank but I am tight for room near the pump. Does anyone know if the tank has to be fitted upstream of all the supply points or can it go anywhere on the system.

Thanks,

Graham


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## wilse (Aug 10, 2007)

would this dufer be OK to fit to shureflo pumps??


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## drcotts (Feb 23, 2006)

wilse said:


> would this dufer be OK to fit to shureflo pumps??


yes mate it will work on any pump. If you can mount it on the end of a run of hose so its in a more conveinient place it wont matter as all its doing is increasing the capacity of the water in the system and as water can be compressed this is what solves the problem.

Phill


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## zappy61 (May 1, 2005)

drcotts said:


> wilse said:
> 
> 
> > would this dufer be OK to fit to shureflo pumps??
> ...


Hi Phil,
Isn't it only suitable diapragm pumps or am I mistaken? So can I fit it anywhere on the system upstream of the pump?

Graham


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## Jezport (Jun 19, 2008)

I am also considering one of these, do you send the water in and out or just T it off the existing pump output?


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## Charisma (Apr 17, 2008)

*Re: fiamma expansion tank*



zappy61 said:


> I am thinking of fitting an expansion tank but I am tight for room near the pump. Does anyone know if the tank has to be fitted upstream of all the supply points or can it go anywhere on the system.
> 
> Thanks,
> 
> Graham


I theory it could go anywhere on the output side of the pump as it absorbs pressure in the pipework which should be the same in all the pipes. I think that it would be best to fit it as close to the pump outlet as possible though.


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## zappy61 (May 1, 2005)

*Re: fiamma expansion tank*



Charisma said:


> zappy61 said:
> 
> 
> > I am thinking of fitting an expansion tank but I am tight for room near the pump. Does anyone know if the tank has to be fitted upstream of all the supply points or can it go anywhere on the system.
> ...


Thanks Dave,

I can get it near to the pump but on the leg to the bathroom. There is not enough room to get it before the branch to the sink without re-plumbing the pump.

Graham


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## PeterM (Sep 24, 2007)

It MUST go on the output side of the pump to be effective. And it matters little WHERE on the output side. In fact as has been said already, you could even add an extension somewhere and fit it there - its acting as a reservoir to damp out pulses.

Peter


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## sallytrafic (Jan 17, 2006)

PeterM said:


> It MUST go on the output side of the pump to be effective. And it matters little WHERE on the output side. In fact as has been said already, you could even add an extension somewhere and fit it there - its acting as a reservoir to damp out pulses.
> 
> Peter


Agreed and to correct one mistake made earlier by another poster its because water CAN'T be compressed that you add an air reservoir.


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## zappy61 (May 1, 2005)

PeterM said:


> It MUST go on the output side of the pump to be effective. And it matters little WHERE on the output side. In fact as has been said already, you could even add an extension somewhere and fit it there - its acting as a reservoir to damp out pulses.
> 
> Peter


Many thanks Peter & Frank,
That is the answer I was looking for. I can put it near the discharge side of the pump but only one branch.

Graham


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## wilse (Aug 10, 2007)

just sJ I can be clear...

Does this gizmo reduce water pressure?
Our pump runs at 30/40 psi [if memory serves].

I would like to keep water flow rate if possible, as it's great for showers.

w


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