Thermal Store Vs Unvented Vs Pump

[nomadtech]

Evening all,

Just in the process of doing a loft conversion, and adding another bathroom. I have has poor water pressure and flow, cold water will drop if more than one tap on. The lead pipe outside has been replaced and where possible inside, it has been changed to 22mm. I am on the first floor of a converted house.

So with the possibility of having a bath and shower running at the same time, considering the three above. There is a boiler (combi) in situ that will be replaced. What I am after is storage to prevent a sudden drop.

- Unvented concerns that there may not be enough pressure and size of the things
- Thermal Store - well the life of them compared to unvented and still need a tank
- Pump of sorts somewhere in the system

Recommendations?

Thanks

Dan

 

[Scott_D]

The incoming main has been replaced and you still have poor flow?

 

[NickDavies]

I suspect (you won't have your own water meter outside and) you are sharing a common incoming mains supply with the other flats in your building, this is one of the major drawbacks of a direct system combined with a conversion that may have been done very well, except for the sharing from a common supply.

I see this quite frequently in parts of London with terraced conversions, I have seen as small as 15mm incoming mains splitting 4 ways to serve 4 apartments in 15mm, of course when the washing machines are on the showers are dribbling and the baths will take 3 days to fill.

If the flow and pressure are as poor as you mention you might be better off referring this to the water board, who will gladly advise you and give you a price to install a meter and thus your own supply.

 

[nomadtech]

Hi both,

Thank for the swift response. Yes, I do believe I am sharing the supply with my downstairs neighbour. I can recall someone suggesting splitting the supply off. Costly and disruptive. Hence if I had a tank/storage cylinder, vented or not, this would prevent digging up the front of the property and relaying it...

 

[lucas121]

A thermal store is only used if you have more then 1 or 2 heat sources.

 

[SimonG]

Stop stabbing in the dark.

Static pressure, dynamic pressure and actual litres per minute.

Get the facts, then decide.

 

[lame plumber]

then install a nice big traditional cwsc as high as you can, sometimes the old ways are best.

 

[Aquazone]

Without knowing your exact pressures and flow rates as Simon has said, you are asking for trouble with a mains pressure system (unvented cylinder or combi) on a shared supply.

Lame has hit the nail on the head, fit a cold water storage tank high up, a vented cylinder and a pump if you wish.

 

[nomadtech]

Hi all,

Thanks for the responses so far, I have been away. My flow rate is around 12 litres per minute from the kitchen tap. I understand that is quite low and explains why flushing a toilet causes mayhem. And the rate is probably too low for an unvented system.

Options therefore are:
1: Break off the shared supply with my neighbour at the supply outside, probably £1 to £2k but this will boost all water
2: Install a 500L accumulator tank that supplies a toilet or/and shower. About £700 for a unit of this size

The boiler itself needs replacing, it is an Alpha 240e, so not sure if that unit is constricting the problem as it is old. If I do go for option 2, would a system boiler be better than a combi?

Finally Shower downstairs took 2.5 minutes to fill a 15 litre bucket.

Thanks again.

 

[nomadtech]

All,

Have done some further reading. Leading towards a system boiler, with a CSWC and a vented cylinder. Dimensions for the latter two would be enclosed within a 800mm wide and 1800mm unit. So not sure whether to go for two units or a combination cylinder?

The alternative is to use restrictor valves on the toilets so the water doesn't drain as fast.

 

[Riley]

Hello mate I would seriously get some guys in to quote.