Mixing Valve and Anti-thermosiphon Loop

[velvetfoot]

My buffer tank/water heater (German) came with this direction:

"When installing a mixing valve, locate it at the bottom of antithermosiphon
loop at least 24” high to prevent excessive hot water from
entering mixed water supply."

The mixing valve they're talking about is for anti-scald.
I've done antithermosiphon loops before, and I can see the mixing valve below the loops, but what does the 24" mean? I guess I'll look up directions for any old water heater-must be similar as far as these components' location go.

 

[Bob Rohr]

My buffer tank/water heater (German) came with this direction:

"When installing a mixing valve, locate it at the bottom of antithermosiphon
loop at least 24” high to prevent excessive hot water from
entering mixed water supply."

The mixing valve they're talking about is for anti-scald.
I've done antithermosiphon loops before, and I can see the mixing valve below the loops, but what does the 24" mean? I guess I'll look up directions for any old water heater-must be similar as far as these components' location go.

Pipe from the hot connection, drop down 24", come back up to the valve. Looks like a P-trap.

Or get a mix valve with checks added into the tailpieces.

I think to meet the ASSE listing the checks need to be part of the installation.

 

[velvetfoot]

Thanks very much Bob! Again! I had ordered the one without the check valves (and temperature gauge). It seems the additional 30 bucks is well worth it. I'm trying to correct the order.

 

[Bob Rohr]

Thanks very much Bob! Again! I had ordered the one without the check valves (and temperature gauge). It seems the additional 30 bucks is well worth it. I'm trying to correct the order.

remove the plastic checks before you solder. Cool down the brass and slip the checks back in for assembly.

 

[velvetfoot]

Again, ditto with the thanks.

 

[velvetfoot]

Bob,
Can I ask another question?
The directions on the Caleffi anti scald valve I just got say to not support the valve with the connecting pipes. Because of where it has to be, there'd be a long hanger rod from the ceiling supporting it, but there's not an easy place to hook onto the valve, without it looking too goofy. Is there a certain accepted way to do this? I can see a similar issue with the boiler protection valve. I also would kinda think that if the pipes connected to the valves are adequately supported, they shouldn't have a problem holding up the valves, but there are indeed unions involved, so maybe not.

Thanks.