Electric under sink water heater

[shannow]

Hi there
I’ve bought a Perfect WIJAS 5.5 under sink instantaneous electric water heater for a bathroom sink
We’ve installed it but it won’t work
The bathroom is in a flat and gravity fed by a tank in the loft
It says it requires 1 bar pressure which there is because I’ve measured it still there doesn’t seem enough pressure to activate it
Any advice much appreciated
Cheers steve

 

[Newboy]

1 bar pressure from a loft tank seems unlikely - equates to around 35' head.

You say that the heater 'doesn't work' - what's actually happening/not happening?

What are the power supply arrangements for the heater (5.5kW)?

 

[gasbusters]

The heater will likely have a switch that only activates at a certain pressure, similar to electric showers.

If its wired in properly, and you have power at the unit, then its simply a case of the water pressure just not high enough to activate the unit.

 

[Nige F]

1 bar pressure from a loft tank seems unlikely - equates to around 35' head.

?

It's possible the block of flats has roof cisterns feeding all the flats .......and the OP is on the ground floor of a 3 storey block

 

[Deleted member 267285]

I’ve looked this up,and unles I’m looking at the wrong product, it doesn’t mention a minimum pressure, it a minimum activation flow rate of 1.6 litres per minute?

http://wijas.com.pl/perfect-3500-4000-4500-5000-5500-en/?lang=en

 

[Alec_t]

It says it requires 1 bar pressure which there is because I’ve measured i

Normal atmospheric pressure is about 1 bar. Methinks the required water pressure is 1 bar gauge, i.e. 1 bar above atmospheric.