Low incoming flow/pressure. Stick with vented, or boost pressure to unvented?

[Ch_152]

A follow on from a previous post.

I have now established that the incoming water pressure/flow rate cannot be increased to my flat. A common problem in this development. The incoming pressure entering my property is ~1 bar and 5 l/m - this is at ground floor.

Currently have an electric shower upstairs which provides terrible (around 2.5 l/m) flow. I would like to run this off stored hot water as I am on an Economy7 electricity tariff.


Am I better off:
- Upgrading my vented cylinder (which is fairly small capacity and poorly insulated) and pump (which is noisy). Any suggestions for a pump would be great.
- Installing a thermostatic power shower (although not sure how this would be piped if HW to the rest of the outlets in the property are being fed off the pump?)
- Moving to an unvented cylinder with something before it to boost pressure into the cylinder. Probably no room for an accumulator though, is this even possible?


Thanks


Chris

 

[cross thread]

Decent size cold water storage tank ,decent lagged cylinder and negative pump without seeing the job is my opinion

 

[Johntheo5]

A follow on from a previous post.

I have now established that the incoming water pressure/flow rate cannot be increased to my flat. A common problem in this development. The incoming pressure entering my property is ~1 bar and 5 l/m - this is at ground floor.

Currently have an electric shower upstairs which provides terrible (around 2.5 l/m) flow. I would like to run this off stored hot water as I am on an Economy7 electricity tariff.


Am I better off:
- Upgrading my vented cylinder (which is fairly small capacity and poorly insulated) and pump (which is noisy). Any suggestions for a pump would be great.
- Installing a thermostatic power shower (although not sure how this would be piped if HW to the rest of the outlets in the property are being fed off the pump?)
- Moving to an unvented cylinder with something before it to boost pressure into the cylinder. Probably no room for an accumulator though, is this even possible?


Thanks


Chris

You mentioned a installed pump?, does it pump both hot and cold? can you provide details of this.

If you wish to install a power shower with its own integral pump then you could install a Triton AS2000 XT which takes cold water from the cold water supply tank and hot water from the HW cylinder and will give up to 14LPM flow.

 

[Ch_152]

You mentioned a installed pump?, does it pump both hot and cold? can you provide details of this.

If you wish to install a power shower with its own integral pump then you could install a Triton AS2000 XT which takes cold water from the cold water supply tank and hot water from the HW cylinder and will give up to 14LPM flow.

Hi. Yeah, it's a salamander CT Force 15TU, pumps both hot and cold to taps and the shower over bath. Not sure if an installation problem, but it's very loud - can be heard throughout the building. The flow from it is fair, but takes a while to kick in sometimes and could be better.

Stupid question (not a plumber) but how would the power shower work with the pump also installed for the rest of the property? Would you just split the take off from the CW tank and HW cylinder with one going to shower and one going to the pump? Wouldn't that cause issues if running both at the same time?

Decent size cold water storage tank ,decent lagged cylinder and negative pump without seeing the job is my opinion

Probably what I thought would be the case. Cheers for the reply

 

[Johntheo5]

Hi. Yeah, it's a salamander CT Force 15TU, pumps both hot and cold to taps and the shower over bath. Not sure if an installation problem, but it's very loud - can be heard throughout the building. The flow from it is fair, but takes a while to kick in sometimes and could be better.

Stupid question (not a plumber) but how would the power shower work with the pump also installed for the rest of the property? Would you just split the take off from the CW tank and HW cylinder with one going to shower and one going to the pump? Wouldn't that cause issues if running both at the same time?

Better off IMO to install a 3.0bar negative head pump like a Stuart Turner Monsoon which will increase your flowrates by over 40% plus upsize your HW cylinder. You could then also supply your existing electric shower from the pumped cold water outlet if low pressure is the existing (elect) shower problem, you said the flowrate is only 2.5LPM which means that even a 8.0kw shower can only be run on 1/2 power?. If it is a 8kw shower then you will still only get 3.2LPM in the winter and ~ 5.2LPM in the summer to achieve a showering temperature of 40C no matter what pressure is available. You could uprate to a 10kw shower which may require wiring mods to give you 4.0/6.9LPM winter/summer at 40C.

 

[Ch_152]

Better off IMO to install a 3.0bar negative head pump like a Stuart Turner Monsoon which will increase your flowrates by over 40% plus upsize your HW cylinder. You could then also supply your existing electric shower from the pumped cold water outlet if low pressure is the existing (elect) shower problem, you said the flowrate is only 2.5LPM which means that even a 8.0kw shower can only be run on 1/2 power?. If it is a 8kw shower then you will still only get 3.2LPM in the winter and ~ 5.2LPM in the summer to achieve a showering temperature of 40C no matter what pressure is available. You could uprate to a 10kw shower which may require wiring mods to give you 4.0/6.9LPM winter/summer at 40C.

Interesting, thanks for that. I didn't know if you'd be able to pump into an electric shower? I think my current electric shower takes mains only: a 9 kW Mira.

I should add that the 2.5l/m was with the shower set to Eco mode and the temperature turned up about half way. With the shower set to "high" and the temperature all the way down (still too hot to shower under!) it was around 4 l/m.

I'd much prefer to use the stored hot water for the shower if possible. Whether that be from a pump like the ST Monsoon, or a thermostatic power shower. The power shower has a benefit in that the main pump is located in a utility cupboard in the spare bedroom - a bit annoying for anyone in there.

 

[Johntheo5]

Your shower doesn't care where the water comes from, the mains pressure is too low to give you the required flowrate with shower on full power, which you would allways require with only 9kw thermal power available, the monsoon will provide bags of pressure but you will still "only" get
3.8LPM in winter & 5.9LPM in summer to give a showering temp of 40C, some people find this quite satisfactory and you will find a big improvement from Eco (1/2) power flowrates of 2.0LPM/winter & 3.0LPM/summer.

A power shower taking hot water from the cylinder will give almost any flowrate you require, anything > 10LPM is considered a power shower and the monsoon will provide the pump power necessary for this.

Don't know what you mean by the below?
"Whether that be from a pump like the ST Monsoon, or a thermostatic power shower."

 

[Madrab]

There are 2 different types of shower that uses a pump - a pumped shower where it uses a remote pump to drive the supplies and a power shower which looks like an electric shower but has a built in pump. If you have stored hot and cold water and the shower pump in the cupboard is too noisy then a power shower will deliver a more than adequate shower with reduced noise @ POU. Triton also do a 'silent running' power shower - AS2000SR - Not sure if it would be 'silent' but it must be pretty quiet to claim that.

You don't want to double pump as it can cause real problems, rather have a separate supply to the shower, a pro just needs to track the pipework and see if it can be decoupled or run new supplies.

You can also pump the mains up to 12L/Min @ ~1.5bar but as you are in a development then that may impact other residents on the same main, all depends on those mains figures being a true dynamic picture.

 

[Johntheo5]

The TritonAS2000SR is known as the Triton Novel here and is reasonably quiet, does give very good performance of up to 14LPM but obviously requires both hot and cold supply.

Adding a Shower (Electric?)

Hello all, I'm looking to install a shower into the house. Currently there is only a bath. There is a cold water tank in the loft space which I assume mains pressure enters, with two outlets. There is also a hot water tank on the same floor as the bathroom. Which is heated by electric...

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