shower pump query.

[powervan man]

Got a customer who had a cheap alterna shower pump fitted 2 years ,it starts off okay but after a few minutes gets really noisy. The hot is off an essex flange and cold is dedicated supply all in 15mm .The question is do i just fit a better quality pump or should i change all the pipework to 22mm . The pipework runs for about 5m up an over in the loft (below tank stollage) .

 

[craigallan90]

the pump should be fitted below or at the bottom of the cylinder. And if the hot is connected to an essex flange off the cylinder that would be the secondary return?? the hot should be connected to the hot draw off from the cylinder. And am sure they ****ty pumps from graham's have a 15 mm connections on them anyways. Also would check the maximum pipe run length from the pump, as per manufactures instructions.

 

[powervan man]

Hi thanks for reply .The pump is on the airing cupboard floor. Cant get hold of manufacturers instructions or find a technical helpline for alterna !Most pump manufacturers are okay with essex flange connections .I'm more concerned about the pipe sizing i'm trying to keep the cost to the customer as low as possible.

 

[craigallan90]

mmmm. I know that but they alterna pumps a nightmear and mira ect do not recommend side entry on cylinders expect that will be the same A drop in cylinder water level could
expose a top entry immersion element. Air in water gathers at the edge of the
cylinder, and in the centre, during the heating process, before travelling up the
vent.. Have you tryed airing the pump ? Is the hot water to hot? The use of hot water above 60C is not recommended as this may lead to an increased risk of cavitation, (air bubbles) which increases the pump noise generate .

 

[WHPES]

And if the hot is connected to an essex flange off the cylinder that would be the secondary return?? the hot should be connected to the hot draw off from the cylinder.

What nonesnse! The hot is preferable from an essex flange than from the hot draw off from the cylinder.

Secondary return??? what you talking about??




Make sure the header tank isnt starting to run dry after a few minutes.

15mm over 5m is fine for a low flow rate pump provided there aren't too many twists and turns. Would not suddenly affect it after it has run OK for a few mins if it were the problem.

 

[craigallan90]

See if you check instructions for other shower pumps it says in it that an extra connection on the cylinder via an essex flange is not prefered, and an essex flange located on the top 1/3 of the cylinder can also be used as a secondary hot return. Goolge it!! And I hardly think its going to empty the cold water storage cistern in a 'few minutes'. So it must be drawing in air somwhere.

 

[Spike295]

The pipework installation sounds pretty much spot on to me, an Essex flange is perfect for the job. If it were my job i'd try running the pump on cold only to start & see if the pump gets noisy, repeat running on hot only. If the pump is only noisy on hot only, i would querie the water temp as the impellar tends to expand if the water is too hot, slips on the shaft creating noise. If the pump is noisy under hot & cold conditions i would change for a decent pump...Stuart Turner & so like.

 

[powervan man]

The pipework installation sounds pretty much spot on to me, an Essex flange is perfect for the job. If it were my job i'd try running the pump on cold only to start & see if the pump gets noisy, repeat running on hot only. If the pump is only noisy on hot only, i would querie the water temp as the impellar tends to expand if the water is too hot, slips on the shaft creating noise. If the pump is noisy under hot & cold conditions i would change for a decent pump...Stuart Turner & so like.

Okay thanks for that advice, i would go for a Stuart Turner pump but they recommend 22mm pipework so i would have to virtually replace the whole installation .

 

[dai the plumber]

Hot should always be supplied from an Essex or similar (warix) flange and I agree that over such a short run 15mm should be adequate. Have you checked to make sure the feed is from the correct outlet on the flange, should be the side one not the top, I've had a couple of Diy'rs fit them incorrectly. If fitted back to front it will suck air which is the death of a low end pump.