Extension with new boiler system

[matthew241277]

Hello,

First time in these forums and it’s a question I’m afraid…

I am in the process of having a downstairs kitchen, side extension and loft conversion to my semi and have to date received some contradictory and confusing advice from various plumbers we have had round to quote for the work.

Basically, I would like high pressure, hot and cold water throughout my house (4 beds with 3 bathrooms, including an en suite in the loft). I currently have a Combi which is not big enough for the new extension and needs replacing.

One plumber has suggested a new condensing boiler (Worcester-Bosh) along with a Megaflow type system and an accumulator (I think to pressurise the mains cold water, to keep the system in balance).

Another plumber has said an accumulator wouldn’t make any difference and we should replace our mains pipe from our property, out to the road. They also said that unless our mains water ‘bar’ and ‘volume’ do not meet a minimum standard, there is no point using a Megaflow as the system will not be balanced.

I would also like to add a water softener and maybe filter to the system (somewhere!) and wondered how this would impact on any of the above?

Does anyone have any opinions and / or suggestions on any of this? Your comments would be much appreciated.

Thanks
Matthew

 

[DP]

What is your CH load?

Megaflow needs good mains pressure. If this is available, new pipe to street mains is a good idea. Couple to existing boiler (if CH loading correct). Let boiler supply HW needs for the kitchen (and utility if needed)

Pressure reducing valve on all UV cylinders give balanced feeds.

 

[gas4you]

In a ideal world you will need at least 3 Bar mains pressure and 20 l/min to get the best performance from an unvented cylinder along with a 22mm cold feed to it.

Saying that, last week I fitted one with only a 15mm supply to it and because they had really good pressure it worked really well. Customer didn't want to pay to upgrade to a 22mm supply.

Customers wife complained that shower was too powerful

As I always say go for the Vaillant Ecotec Plus 600 range with a Unistor cylinder, a VR65 controller and VRT360 programmable room stat for the lastest and best in efficiency and control.

For 3 bathrooms I would recommend the Unistor 260.

 

[matthew241277]

Thanks guys. So if my mains pressure is not sufficient, would an accumulator get round the problem?

Thanks
Matthew

 

[gas4you]

I believe so, but I know nothing about them. Simond on here has fitted loads with his company so is expertly placed to advise you if he comes on here.

 

[Agile]

An accumulator would have to be VERY large to help with filling baths. Its useful for basins etc. though.

In my view for most applications an upgraded supply pipe is the way to solve the problem.

The genuine Megaflow's air bubble does give an accumulator effect for basins but this runs out after about 10-20 litres.

Tony

 

[matthew241277]

Thanks again guys.

Given the cost of upgrading the supply pipe (up to a grand?), would an accumulator be a reasonably priced alternative? Unless anyone knows of any others?

Cheers

 

[gas4you]

Contact Simond via his profile

 

[Agile]

The difference is that an accumulator has a very limited usage until its advantage ceases.

An upgraded mains supply will work 24 hrs a day giving an inproved flow rate not 5-10 minutes!

Tony