heatrae sadia 25l 9004010.

[Matt0029]

It’s gravity by the sounds of it so solenoid needs to open when the tap is opened so sensing issue eg where the water is i would say

So even though the solenoid opens to fill and shuts when the unit is full. It also needs to open when a hot tap is opened to allow the cold main to push the water out of the unit?

 

[ShaunCorbs]

So even though the solenoid opens to fill and shuts when the unit is full. It also needs to open when a hot tap is opened to allow the cold main to push the water out of the unit?

Unless it’s a gravity out unit

 

[Matt0029]

What's gravity out imply please? It's mains feeding it. Thank you

 

[Matt0029]

Do you mean gravity out as in feed from a storage filter?

 

[ShaunCorbs]

Do you mean gravity out as in feed from a storage filter?

Yes from the heater

 

[Matt0029]

Thanks so it can be mains in and still classed as gravity out?

 

[ShaunCorbs]

Thanks so it can be mains in and still classed as gravity out?

Could be might be worth phoning heat rae

 

[Matt0029]

Thanks I'll give a ring. I have the manual there is a filter on the cold main in it. There a low and high water level sensor that opens and closes the solenoid. Which must be working as opened to fill it and shut off when full. And said took a long time to fill the 25 litre tank.

 

[John.g]

I came across a ~ 20L heater with no expansion vessel that had one of these pressure relief valves set to I think 6 bar but it also had a anothenon return valve valve inside the PRV to enable filling and also stopped the cylinder emptying in the event of mains water failure, it didn't have any solenoid valves and allowed the expansion to take place back through the mains with a minimumm distance specified to avoid hw water issuing from a cold tap if too close, don't know how your cylinder operates, its hardly a gravity unit if it requires pressure to push the water out of it?

Ariston 571730 PRV installed on the cold inlet at the cylinder.

 

[Matt0029]

It has a high and low water pressure sensor on the unit linked to the solenoid valve

 

[Matt0029]

When I turn the hot tap on the solenoid is in the closed position. As this operates then the low water level sensor opens it again. So if opening the hot tap and the solenoid is closed. It would be gravity?

 

[Matt0029]

First time I've come across one like this before there expensive units

 

[John.g]

If it gravity then there has to be a air vent in the cylinder to allow the level to drop to fall enough to open the solenoid valve? maybe it contains a air bubble like the megaflo and the like?
Are there HW draw offs above the cylinder or on the same level?

 

[Matt0029]

It has a breather pipe coming out of the top. With no valve on it.

 

[John.g]

Is it a vacuum breaker?, if so, then any HW draw off has to lower than (at least) the level of of the low probe.