Combi boiler question regarding hot water

[zsoltimatrix]

Hi guys,

Could somebody help me out with this please?

I am planning on installing a combi boiler (greenstar 42CDI) with 17.2 on 35° hot water flow.

The boiler would be around 8m away from the bathroom. Provided that the mains water pressure in the house is good, is this an acceptable distance to have high pressure mixer shower in the bathroom?

Alternatively I could move the boiler to the bathroom but that would be very expensive because of all the alterations to be made to the pipe work.

What do you guys think?

Thanks,

 

[macackau]

Pressure is one thing but what are the static and dynamic water flow rates in your property? If you want a flow rate of 17.2 litres you need to make sure you have 20+ litres supplying your property.

 

[macackau]

Should have said the reason I'm asking is if you only have a flow rate of 15 litres you won't get a boiler flow rate of 17.2 litres. You also want to be able to shower and the shower not be affected by somebody running a tap or flushing a toilet for example.

 

[thompsonbrown]

Should have said the reason I'm asking is if you only have a flow rate of 15 litres you won't get a boiler flow rate of 17.2 litres. You also want to be able to shower and the shower not be affected by somebody running a tap or flushing a toilet for example.

Totally agree and to expect 17.2 ltrs from boiler, your incoming mains pressure should exceed 30 lpm

 

[Silent Dancer]

If you want to guarantee a good mains feed shower go down the invented cylinder route. If there is the space then yes fit a high out put combi not will the water mains need checking but also gas supply. This is a thy wmaximum end of a domestic supply.

 

[buckley plumb]

Check working water pressure worcesters need about 2 bar working on 52 cdi to give full flow from memory. I went to a house where they had fitted 42 cdi they had 12 litres at 1.3 bar coming in. They could have fitted a 30 kw boiler

 

[zsoltimatrix]

Hi guys,

Thanks for all the replies, I will try to check those numbers once we are in the house.

However, let’s say that I do have a good pressure and everything else, is the 8m distance to the bathroom a problem?

 

[Dsp]

Hi guys,

Thanks for all the replies, I will try to check those numbers once we are in the house.

However, let’s say that I do have a good pressure and everything else, is the 8m distance to the bathroom a problem?

It's a fair run that you want to do in as large bore and lowest number of couplings reasonably possible and insulate it well

 

[zsoltimatrix]

It's a fair run that you want to do in as large bore and lowest number of couplings reasonably possible and insulate it well

Well, the hot water oulet on the boiler is 15mm. It would be a straight run, up in the loft and dow and it would be insulated.

 

[Dsp]

You say you will be installing the boiler ?? Are you GSR??? Shouldn't your installer be giving you the advice and support and doing the correct tests before advising what to fit??

 

[Stanios]

An average showerhead wont push out much more than 15 litres a minute anyway, unless you are planning on running several hot taps at the same time as the shower i'd stick to a 30kw combi