Installing single 2.0 bar pump, please help

[ChapeL]

Hi,

I'm planing to add 2 bar single pump to my hot water system, I've tried to have a plumber to come around but two were not interested as the job is "too small", one never showed up and the other didn't seem to know what surrey flange is. So I've decided to do it myself.

I've been reading online trying to understand what exactly needs to be done, I want to boost the pressure to all my hot water outlets (kitchen tap, two in the bathroom) and replace my old electric shower with a thermostatic one.

I have gravity fed system and so far I know I need to add surrey flange and single impeller pump, my questions are:

1) My cold water storage tank is 4 gallon, is it sufficient or needs to be changed?

2) I've read somewhere (can't find it now) something about shower head needing to be at least 1m below bottom of my cold water tank. This is not possible in my case, I live in a flat and bottom of my tank is at 1,65m and shower head will be at 2.2m. Could someone clarify this to me? I think I'm getting confused as cold water will be fed from my cold mains and hot water from my new pump.

3) Is this pump ok?
http://www.stuart-turner.co.uk/products/monsoon/u20-bar-single/
or cheaper one like this will be enough:
http://www.stuart-turner.co.uk/products/showermate-eco/s20-bar-single/

4) My mains cold water pressure is at 3.2 bar, I understand that for thermostatic shower I need to have equal pressure, will Pressure Reducing Valve set at 2 bar (same as pump) do the job?
http://www.screwfix.com/p/honeywell-pressure-reducing-valve-with-gauge-22mm/32536

Any advice will be greatly appreciated

 

[longdogs]

I know I will probably get blasted for this but I have never used any form of flange when fitting a pump. I have always teed off the DHW pipe from the top of the cylinder and have never had a problem. In fact, I would go as far to say that whenever there has been a problem with air in the system, it has always been when a flange has been fitted. That's just my experience so far.

Some pump manufacturers insist that you fit a flange or their warranty is invalidated, some don't so you would need to check the installation instructions.

Tip: I normally install a bypass into the pipework so that if the pump fails and has to be removed for any length of time, you can switch to the by-pass for continuous water. A bit OTT maybe but I just prefer to do it.

 

[muggles]

Go for the 3.0 bar - it's £1.50 cheaper and will better match your system
http://www.bellabathrooms.co.uk/stu...versal-single-3-0-bar-negative-head-pump.html

You'll need more than 4 gallons of stored water - with a pump on that'll be drained in no time.

Your pump should be 1m below the tank as a minimum but the shower head can be above it.

I'd use a Surrey flange or similar, but Stuart Turner do permit installation by teeing iff the existing hot water distributing pipe I think. Check the installation instructions online for confirmation

 

[ChapeL]

Go for the 3.0 bar - it's £1.50 cheaper and will better match your system
http://www.bellabathrooms.co.uk/stu...versal-single-3-0-bar-negative-head-pump.html

Great, so I won't have to fit pressure reducing valve on my thermostatic shower, correct?

You'll need more than 4 gallons of stored water - with a pump on that'll be drained in no time.

What size would you recommend? I have 220l bathtub so this is going to be the most continuous use of hot water.

Your pump should be 1m below the tank as a minimum but the shower head can be above it.

Got it, thanks.

I'd use a Surrey flange or similar, but Stuart Turner do permit installation by teeing iff the existing hot water distributing pipe I think. Check the installation instructions online for confirmation

Just to confirm that Surrey flange is ok, this is how my system looks like now:







Thank You

 

[TeaTime]

Pictures aren't showing.

 

[ChapeL]

Pictures aren't showing.

Hmm strange they do on my end How about now?

 

[muggles]

You shouldn't need a pressure reducing valve with the 3.0 bar pump, although nothing is entirely guaranteed. What you do need to do, though, is fit double-check valves to your mixer taps' cold supplies to prevent hot water being pumped into the mains.

As for cold water storage, I'd say 35 gallons as a bare minimum, anything less than that and you risk running your pump dry, which will do it in and invalidate the warranty. Stuart Turner pumps are excellent but they are extremely....particular....about the installation conditions when considering warranty claims.