1.5 Bar QUIET negative shower pump recommendations please.

[dupfold]

Hello

Due to the size of my storage tank I've been advised the most I can have is up to 1.5 bar. I've been searching online for Stuart Turner 1.5 but found that they only come in either 1.0 or 2.0 bar, plus are also very expensive and heard they are quite noisy.

I'm quite keen on the Techflow Negative Twin QT45/NH 1.2 Bar but wondering if there is a real noticeable difference between 1.2 and 1.5 bar?

I will more than likely be using this with the Mira Excel Thermostatic Shower BIV and therefore require a strong enough pump to make use of the Excel features such as Soothe, Force, and Eco spray patterns, otherwise I may as well just opt for the cheap Mira Silver Thermostatic Shower BIV.

Your thoughts please.

 

[D_Hailsham]

Mira Showers have a pump listed, but it does not say if it is suitable for a negative head.

Why not give Mira a ring and ask their advice?

 

[Gasguru]

Techflow QT range are considerably quieter than the ST pumps.

 

[dupfold]

Thanks guys.

Is there a real noticeable difference between 1.2 and 1.5 bar?

Neither Techflow or Stuart Tuner do a 1.5 version and The Techflow QT only comes in either 1.2 and 2.3, the later of which would be too much for my storage tank.

 

[Gasguru]

I would imagine the 1.2 Bar QT pump would be adequate but I suggest you speak to Mira technical since the flowrate/pressure diagrams are ambiguous between the valve and showerhead manuals (they also supply different flowrate adapters). They will need to know the height difference between the shower head and cold cistern and size of vessel.

 

[dupfold]

Thanks. After speaking to plumber today I'm going for either 2.0 Stuart Turner or 2.3 Techflow QT as he confirmed this will be ok with my cold cistern and vessel size.

I'm swaying towards the techflow as its a little quieter than the ST and slightly cheaper.

 

[simond]

I would have thought you would rate shower pumps on how 'noisy' they are.

None of them are 'quiet'.

And the faster the pump, the noisier they get. The 1.5bar therefore would be less noisy, less cavitation at the impeller tips.

 

[BigBurner]

A £400 I would give the ST pump a big miss and go for one of these, which is virtually silent:
http://www.heatweb.com/products/showermaster/showermaster.htm
Gives mains pressure showers.

Or fit an accumulator for the shower only - if possible.

 

[dupfold]

I would have thought you would rate shower pumps on how 'noisy' they are.

None of them are 'quiet'.

And the faster the pump, the noisier they get. The 1.5bar therefore would be less noisy, less cavitation at the impeller tips.

Fully understand that none are quiet, however some are noisier than others. By searches on this forum I have found a number of people complaining that while the stuart tuner pumps are excellent they can be very noisy.

I did not know about the higher the bar, the more noise it would make so will bear this in mind, thank you.

 

[Gasguru]

Forget the DPS system...you need a high ouput boiler to operate the shower head you plan to use (which is why combis are 24Kw or more). Even if the boiler was suitably sized with a cast iron boiler there will be a significant delay for the shower to get up to temperature. There is also risk of corrosion to the heat exchanger and flue since the return temperatures are very low.

I still maintain the QT pump is significantly quieter than the ST pumps (certainly the showermate range). I happened to temporarily fit a 1.4 Bar showermate pump for a customer...a week later I replaced it with the 2 Bar QT80-2 pump. The reduction in noise was considerable. For a given pressure rating the Techflow pumps also perform better...the pump curves remain more horizontal over a given flowrate range.

You could also mount the pump on a paving slab sitting on foam (outdoor camping mats....cheap)

 

[dupfold]

I'm sold!

Never had a shower pump before so is the installation rigid due to pipe etc or can I place a paving slab underneath after if required?

 

[BigBurner]

Forget the DPS system...

I would not forget it at all.

you need a high ouput boiler to operate the shower head you plan to use (which is why combis are 24Kw or more).

They have a version that pumps from the DHW cylinder. Another version that converts the cylinder into a heat bank doing all the DHW in the house, making it all mains pressure.

I would have one of these any day to a screaming power shower pump - that leaks quicker than you think.

There is also shower coil cylinders - a mains coil in the top of a vented cylinder. Not sure of prices these days.

Also a combi and use the DHW section for the shower. If the boiler is old replacing with a combi small kW combi for the shower may be the way forward.

 

[Agile]

Geoff, this fellow has a storage cistern and therefore one assumes a hot water cylinder so the HW consumption rate will only be limited by the length of shower he wants to get per cylinder full.

I have always thought the Watermill pumps were some of the quietest.

A layer of foam rubber under a 50 mm paving stone will prevent most of the transmission noise into the floor.

However, dont be tempted to encase the whole pump in a box. I once saw one and the pump control PCB had overheated and failed.

Tony

 

[Gasguru]

The pump comes complete with flexible hoses to dampen vibration and allow easy servicing if necessary but they are installed vertical so you can't add a slab afterwards without shortening the copper pipework.

I suggest you have FULL bore lever isolating valves (not gatevalves) fitted to all connections and use the Techflow flange to get the extended warranty. The slightest air entry to the pump (normally from the hot side) will reduce performance and can prematurely wear the bearings.

Read the manufacturers instructions...and adhere to them

 

[Gasguru]

Yes I have fitted watermill pumps before (the low voltage range) but I can only go by current experience (and of others know that bathroom fit full time).

Since the OP requires a negative head pump I'm assuming he may have a pre-fab arrangement with the cold cistern directly above the cylinder where capacity may be limited.

Bigburner aka watersystems

A pump is around £230 + flange. All your options will complicate the installation and are considerably more expensive (and beyond the knowledge of most installers). "screaming shower pump"...not really, actually fairly quiet.