heatrae sadia 25l 9004010.

[Matt0029]

Has anyone one fit or serviced one of these before; Heatrae Sadia 25l 9004010.
It a 25 litre hot water storage cylinder.

 

[Matt0029]

Seems to have what they call a breather pipe coming from the top of it to a tundish. Appears to have this instead of an expansion vessel.

 

[ShaunCorbs]

It’s just an unvented unit internal t and p valve you need a min of 3m of pipe on the outlet

 

[Matt0029]

Is that 3 meters of pipe on the outlet for expansion?

 

[Matt0029]

It seems to have a solenoid valve on it for filling. I have one to look at that apparently isn't filling. Wondering if this could be the issue.

 

[Matt0029]

Mentions the solenoid valve there about no water flow. Suggests more electrical. Any idea how to test?

 

[ShaunCorbs]

Mentions the solenoid valve there about no water flow. Suggests more electrical. Any idea how to test?

It will be voltage to the coil could be dc or ac depending on circuit

 

[Matt0029]

Thanks so you would test the voltage to the coil and see if it was within parameters?

 

[ShaunCorbs]

Thanks so you would test the voltage to the coil and see if it was within parameters?

Yes spec or on the side of the coil this should be listed

 

[Matt0029]

Thanks yes there is two electrical connections on the solenoid valve. It would be a case of testing the resistance between these? There appears to be no number that this show be in the instructions. May ring technical

 

[ShaunCorbs]

Thanks yes there is two electrical connections on the solenoid valve. It would be a case of testing the resistance between these? There appears to be no number that this show be in the instructions. May ring technical

Test voltage first if you got voltage then test resistance of the coil to test if it’s bad

 

[Matt0029]

At which connections do you test voltage to the solenoid? I have only ever done resistance across the pins before.

 

[ShaunCorbs]

At which connections do you test voltage to the solenoid? I have only ever done resistance across the pins before.

At the solenoid pins just wiggle the connector off a smidge so you can get probes on etc

 

[Matt0029]

Thanks so it filled and stopped filling so the solenoid valve is opening and closing. It did take a long time to fill. However the flow from the hot taps feed from it is really slow. I was going to take the filter out on the cold feed Im the machine to see if clogged/ clean it. Any other ideas why hot water flow would be really slow.

 

[ShaunCorbs]

Thanks so it filled and stopped filling so the solenoid valve is opening and closing. It did take a long time to fill. However the flow from the hot taps feed from it is really slow. I was going to take the filter out on the cold feed Im the machine to see if clogged/ clean it. Any other ideas why hot water flow would be really slow.

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

 

[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.

 

[Matt0029]

Thanks yes the draw off are all lower the the unit. Breather pipe has tundish on it.

 

[John.g]

Maybe worth checking that for scale build up, if its restricted then the flow from any hot tap will be restricted as well except its just a pure vent pipe,, any photo or description of the unit?.

 

[Ben-gee]

Check the breather pipe for blockage, kink, hernia.
If air can’t get into the unit - water can’t get out.

 

[Matt0029]

Check the breather pipe for blockage, kink, hernia.
If air can’t get into the unit - water can’t get out.

Thanks I think there is a filter in the breather pipe. But there isn't much distance between the bottom of the unit and the hot taps. Only 1meter tops. So 0.1bar.

 

[John.g]

I have a upstairs "1/2" cartridge tap gravity fed from ~ 0.25M that flows 4.0LPM, so if the water level in your cylinder is, say 0.15M above the tap then you might expect ~ 3.0/3.1LPM.