Hi,
I have just had a new worcester 25si greenstar boiler fitted and I am keen to change my old electric shower for a mira excel. I have read through the instructions for fitting he mira excel and there was a few questions I have and wondered if someone could advise me.
The following is from the fitting instructions:
Instantaneous gas-heated showers (e.g. combination boilers) The shower control MUST be installed with a multipoint gas water heater or combination boiler of a fully modulating design (i.e. where the water draw-off rate indirectly controls the gas flow rate to the burner). A drop tight pressure reducing valve MUST be fitted if the supply pressures exceed 5 bar maintained. An expansion vessel MUST be fitted (and regularly maintained) as shown in the diagram below to ensure that excess pressures do not damage the product. This may already be fitted within the boiler (check with the manufacturer) and is in addition to the normally larger central heating expansion vessel. The hot supply temperature MUST be at least 12 =B0C hotter than the required blend temperature for optimum performance.
My questions are is the 25si fitted with an appropriate expansion vessel? The instructions say it has one but I'm not sure if this is purely for the central heating.
Does the 25si's supply pressure exceed 5 bar and if so how easy is a drop tight pressure reducing valve to fit?
The last question is is this a job for a diy plumber or would it be better for a plumber to do it. The main reason I want to do it is I enjoy diy and get a lot of satisfaction from it, plus I have to tile around the old shower and live without a shower for a few days and dont want to have to rely on a plumber to turn up!
Thanks.