Replacement hot water tank - flat -economy 7

[carlsbergy]

I have a 2 bedroom flat which has electric heating/electic hot water which is on economy 7. The hot water tank is 6ft high with a two elements heating it (night and day) and appears to have a smaller header coldwater tank built at the top of the tank which coldwater tops up the tank via a ball valve. I have replaced the heating elements a few times over the last 10 years. The tank is starting to drip where the bottom element screws in and last time the elements were changed is full of calcium at the bottom of the tank so I intend to replace the tank.

Could I fit a direct tank unvented? or do I need to fit another direct vented tank? What are my options? I have tested the water pressure on the incoming mains and it is 2.5 bar. Any advice would be appreciated. Thanks

 

[muggles]

You need to test your water pressure with a tap running, find out what flow rate you're getting when the pressure gauge is showing 1.0 or 1.5 bar.

You could have an unvented cylinder fitted if the above test is satisfactory (you can't do it yourself as you must be G3 qualified to fit one). Unvented direct cylinders come with up to four elements, although two is more normal.

 

[carlsbergy]

Thanks Muggles, so I would run a tap and monitor mains pressure at 1.5bar, then measure how many litres per minute come out of tap? what is ideal flow rate?

Thanks

 

[muggles]

Yes, and you should be aiming for 20 litres per minute

 

[carlsbergy]

great, thanks muggles