Shower pumps

Hi

I fitted a new mixer shower pump in Feb 2012 to a gravity fed mixer shower. The old pump had worn out, it was a Triton T550. I called triton and they suggested I changed it to the Triton T550i which pumps up to 1.2 bar at 16 litres a minute max.

Had a call a few days ago from the client to say after 4 minutes in the shower the cold stops working and only hot is coming out of the shower.

After investigating I noticed that the feeder tank in the loft is emptying quicker than it is refilling hence the cold water is running out.

I have checked with the water board and they say that the pressure coming from the road is within there acceptable limits but the flow is only 15 liters a minute.

I have tried turning down the speed of the pump but this just delays the problem

The other idea I thought would be to increase the tank size, however the loft opening is very slim and there is no way of getting another tank in the loft.

The only other thing I can think of is getting a less powerful pump?

Can anyone suggest one?? or other ideas

Many thanks

Paul

Have a look at a coffin tank, may be able to get it in.

You could fit a low pressure seating into the ball valve or fit a 3/4 ball valve into the cold water tank.

or even two ballvalves?a round 50/70 tank will go through a hatch thats 600mm measured diagonal so a 25/30 will go through any hatch a man can get through

Any idea what size cistern is fitted in the roof?

Hi

stupidly did not measure it but it is about 3ft in length by 1.5 ft wide by1.5ft deep at a guess

How about doubling the capacity by putting a similar sized tank alongside linked to the existing one?

Go with the 2 x 1/2" float valves, it worked for me & it's cheap (only thing to watch is the dynamic mains pressure will fall while pump is in use)

So if the main delivers 15 litres a minute, and the pump displaces 16 litres a minute, two valves will increase the overall delivery? How does that work?

Does the mains deliver only 15L/M, where was this tested ?? The main restriction is the seating which on a 1/2" H/P float valve is about 5mm dia (not 15mm pipe connection) So flow rate is restricted, by installing 2 you can increase the area, reducing the restriction & increasing the flow rate. If you increase the flow rate (sometimes called recovery) you can decrease the storage. In this case get more out of the cistern before the water runs out due to the use of the shower booster.
Of course you could always install a shower flow restrictor to limit the flow to say 12L/M which will still give a good shower.

if it refils at 15l/m and shower works at 16l/m then the cistern is losing 1 l/m. how long are thier showers if this is emptying the cistern?

According to the sales data, the Triton T550i displaces 11.5 litres per minute?

Is the current valve working as it should be?

Originally Posted by petercj

According to the sales data, the Triton T550i displaces 11.5 litres per minute?

If that is the case, maybe two valves would do the job.

Thing is, will the customer be content to put up with any pressure drop problems when the shower is in use?

More water in the loft sounds the best bet to me.

Sorry peter I know you are going to call me names but pressure will not drop in shower (if anything it will increase) if the flow rate is reduced with a restrictor.

Originally Posted by chris watkins

Sorry peter I know you are going to call me names but pressure will not drop in shower (if anything it will increase) if the flow rate is reduced with a restrictor.

I don't go in for name calling chris, and I know from your posts that you know your stuff.

You were really quick off the mark with your reply, because as soon as I re-read my original post I changed it through 'edit' re checking the current valve in relation to the 11.5 displacement figure given for the T550i, i.e. maybe the current valve is not passing as it should.

Thanks guys for all you comments. The client is a good friend of mine at he seems happy at the moment as all works well if he has showers for 4 minutes or less.

One question

If I teed off the supply coming into the cistern, so I had two supplies coming into the same cistern would that make a significant difference, or would it be better to put another cistern in the loft space and connect the two

thanks

Paul