Megaflo, Thermal Store, or Pump?!

[adamboyse]

Hi (apologies for the longish post)

I'm currently renovating my 4 bed house which currently has a standard vented central heating system with a Potterton Flamingo 50s gas boiler and a hot water cylinder in a bedroom cupboard.

Although I think it's a nice simple system and hasn't caused me any problems other than the usual valve head changes, I'd like to upgrade because it's around 10 years old and due for an upgrade. I also need to move the hot water cylinder from the bedroom because it's taking up useful space.

After speaking to the plumber, he was trying to convice me to go for a combi because it removes the need for any tanks but I managed to steer him clear of this because I've not been impressed with combis before and I need something that can supply multiple taps and a shower with good pressure (he said it would but I don't think it will!).

So, the boiler will probably be a new Potterton condensing (or ideally a regular Suprima if I can it installed before Apr 1st). The next question is what to do with the tank because I need...

- To supply two bathrooms, one of which will need high pressure to supply a "tower shower" (one of those with multiple jets).
- To remove the existing hot water tank from the bedroom (the only other suitable location for any tank is the loft)

Options seem to be...

1. Megaflo in the loft
2. Mainsflow thermal Store tank in the loft
3. (not sure if this is possible) Combi tank in the loft (one with the hot tank below and a cold water tank above it).

Option 1 may provide enough pressure if the mains flow rate is high enough but the install cost will be high and it'll need annual checks.

Option 2 would be slightly cheaper but I've heard these scale up badly.

Option 3 would be ideal if this type of tank can go in the loft because I can simply put a pump on to supply the shower that needs the pressure.

Sorry for the long post - looking forward to getting some advice...

Thanks
Adam

 

[bripl]

mainsflow thermal store would be my preference as i had one for 7 years nothing could touch it for hot water performance or instant heat for the rads never had a problem with scale [bedfordshire] you could run the bath have a shower and wash up with only a small drop in pressure[new house/benchmark/flushed/inhibitor]as well as very low fuel bills,my water bill[metered] was higher than the gas/elec together,look at albion,gledhill thermal stores.boiler was ideal classic 40.

 

[ChrisR]

Well done for doing your homework. Just a couple of points - option 3 would go in the loft but I've never seen one with a very big hot water store. They can be separate tanks if you have enough headroom (unusual).
Also I've never tried to pump from one of those, always fearful that the vent pipe would suck air as there's so little head.

Most impotantly, affecting all 3 options more or less, you have to have enough mains flow to replace what you're using. I've recently lost a couple of jobs because I wouldn't accept it was enough.
If mains pressure is a problem, an "accumulator" can be the answer.

Measure your mains pressure and total flow. Water provider will be able to tell you the pressure from your postcode.