digital shower for a tank system work with a combi boiler?

[shooky]

Hi,

I was wondering if anyone could help.

I have an old boiler with a tank system. i have a Myra Magna digital shower which uses a power shower pump.

I want a combi boiler and have been advised to get a valiant 837 for my house.

The spec sheet from Mira shower says do not use the pumped version of the shower on a combi boiler. There is lots of red warnings in the leaflet and also one on the mixer valve itself on a sticker. However the only explanation I can find in the instructions for the shower seem to suggest its because it may demand more water than the boiler can supply.

However, the boiler outputs 15 Litres a min.

The spec on the equivalent version of my shower mixer but for a combi boiler says you may need an inlet reducing valve if you have a lower spec boiler but if you have a 37 KW boiler (which I will) you do not need a inlet reducing valve. i assume this is because the boiler is big enough to produce the hot water that the shower will demand.

So, (sorry its so long winded) if my plumber takes the power shower pump out of the system and connects my existing digital mixer to the combi boiler, does anyone know if it will work. ? I have a pressure reducing valve at my stop cock if that is relevant at all.

Is my understanding of the reason Mira say not to use my mixer unit with a combi correct ? Other than of course they want me to sepnd £450 on a new unit. Or are there any problems we may encounter by truing this ?

Thanks in anticipation. Hope I have not shown too much of my ignorance !

 

[Morris40]

1) the Ltrs per minute listed on a boiler will pretty much never be achieved this is for benchmarking against other manufacturers so forget 15ltrs per minute,
2) if you pump through a combi the water will go too fast and will not get heated up properly,
3) you can not connect a pump to the incoming mains and you will be indirectly, it's against water regulations