HeatreSadia

[Matt887]

Has anyone fit or worked on one of these units before?

 

[terryplumb]

Haven't worked on that particular model ,but have worked on a couple of it's predecessors.
The hot water distribution is gravity fed,so needs to be fitted much higher than any tap outlets it feeds.

 

[Matt887]

Thanks yes this has a solenoid valve to open and close the flow of water on. Switched on via a high and low water pressure sensor.

 

[Matt887]

Was just trying to get my head around the breather pipe. This is like an open vent pipe?

 

[terryplumb]

Ah ,it's not quite the same as the ones I worked on. There was no solenoid valves ,just a cistern at the top with float valve and overflow .
Immersion heater and stat fitted at the bottom vertically.

 

[Hugh Jaleak]

Breather appears to be a safety vent/discharge pipe, so I would suspect operates via a PRV.

Outlet from Tundish needs to be routed to a suitable discharge point, where possibly boiling water could be released, external is recommended.

https://www.heatraesadia.com/-/media/themes/heatrae/literature/installation-manuals/r-plus-installation-manual.pdf

 

[Matt887]

Thanks there's no prv valve on it or temperature relief just a pipe coming from the top with a tundish

 

[Madrab]

This is like an open vent pipe?

Yes - The 'breather' pipe at the top is open to the vessel and it's under atmospheric pressure - it acts exactly like the vent on a Open Vent HW cylinder

It will only be used when there is a fault condition and the HW overheats and expanding beyond the confines of the cylinder, either that or if the unit overflows say if the fill valve failed open. The water level in the heater is usually controlled by a level sensor operated valve.

As suggested, the vent/breather/overflow pipe needs to be routed to a safe discharge location by pipe that can sustain very hot water.

 

[Matt887]

Is the over flow pipe similar to that of an open vented system header tank overflow pipe then?

 

[Madrab]

Is the over flow pipe similar to that of an open vented system header tank overflow pipe then?

Nope - F&E cistern usually use ordinary waste pipe for it's overflow as it only has to deal with cold or warm water - the HW vessel's overflow may have to deal with >95deg HW in a fault condition - normal waste pipe would start to collapse at that temp if running for any length of time.

 

[Matt887]

Breather appears to be a safety vent/discharge pipe, so I would suspect operates via a PRV.

Outlet from Tundish needs to be routed to a suitable discharge point, where possibly boiling water could be released, external is recommended.

https://www.heatraesadia.com/-/media/themes/heatrae/literature/installation-manuals/r-plus-installation-manual.pdf

Thank you it goes external at the moment but is high level and just stick out. Hate following rough plumbers . Best way of making this safe?

 

[Hugh Jaleak]

Best way of making this safe?

Extend it to a suitable point where any potential discharge wont affect anyone/anything passing by. Ideally would say reroute internally and come through the wall at lowest possible point to reduce risk of freezing in cold weather.

 

[Matt887]

Thanks there is a waste pipe near by 40mm pushfit. But takes 2 sinks. If going into the waste it needs to be it's own leg no other appliances connected

 

[Hugh Jaleak]

As Madrab has said, needs to be done in suitable pipework, waste pipe will not like water at near boiling point for any length of time, it'll sag and/or deform. Personally would do it in Copper tube, no question of it failing then.

 

[Matt887]

I could run down the wall in copper but would be at risk of getting stolen