Thermostatic mixing valves: mounting orientation and safety concerns

Users who are viewing this thread

RustyShackleford

New Member
Messages
2
Reaction score
0
Points
1
Location
NC
I plan to install a Honeywell-Residio thermostatic mixing valve (model AM101-SB-1LF) on a 50gal conventional electric water heater in our vacation house, in order to make more usable hot water available to the 3 bathrooms (4 bedrooms). I've got a couple of concerns ...

1. First, because of the existing plumbing, I'd like to install it with the tempered water outlet pointing upwards; I'm confused about whether this is acceptable, as the instructions are confusing (https://digitalassets.resideo.com/damroot/Original/10014/62-3075EFS.pdf). The paragraph on the lower-right of the first page says "can be installed in any position consistent with the intended use" but then "for domestic hot water supply, the valve must be installed as shown in Fig. 1" and Fig.1 shows the thing oriented with the outlet pointing sideways and the hot and cold coming in from the bottom and top (it's also showing a recirculation system, which I don't have).

2. How fool-proof is the anti-scalding technology ? Especially as the house will be rented a good bit, and small children present when we are using it, I'm concerned about setting the water heater as high as 160. Of course, even 140 gives me a third again as much hot water - if I understand correctly, assuming the incoming cold water is at 60 degrees, since (140-60)/(120-60) = 1.33.
 

Breplum

Licensed plumbing contractor
Messages
1,164
Reaction score
444
Points
83
Location
San Francisco Bay Area
The valve can be oriented in any direction, there is no gravitational influence to worry about. They are very reliable.

It tempers the outgoing water, but is not anti-scald. Always add a thermometer to the installation to allow for accurate adjustments.
The ASSE 1017 standard states that when used, "They should be supplemented by a point of use device to control final temp to fixture".
In other words, you should have an anti-scald shower valve, which all modern pressure balancing or thermostatic shower valves have.
As far as faucets, in residential settings, the additional protection is not legally required and virtually never done.
 

Terry

The Plumbing Wizard
Staff member
Messages
29,939
Reaction score
3,400
Points
113
Location
Bothell, Washington
Website
terrylove.com
I really like this one for water heaters, a super easy installation.

honeywell_amx300_02.jpg


The one below is not my install, but does show a different way.

honeywell_tempering_2.jpg


tempering-valve-tub-terrylove.jpg


This one under the bathroom sink for the soaking tub.

am-1-series.jpg


index.php
 
Last edited:

Terry

The Plumbing Wizard
Staff member
Messages
29,939
Reaction score
3,400
Points
113
Location
Bothell, Washington
Website
terrylove.com
2. How fool-proof is the anti-scalding technology ? Especially as the house will be rented a good bit, and small children present when we are using it, I'm concerned about setting the water heater as high as 160. Of course, even 140 gives me a third again as much hot water - if I understand correctly, assuming the incoming cold water is at 60 degrees, since (140-60)/(120-60) = 1.33.
I have installed quite a few, so that the water heater could be turned up but then safely put out water at 120. It's a big help for filling that bathtub or squeezing in an extra shower or two.
 

RustyShackleford

New Member
Messages
2
Reaction score
0
Points
1
Location
NC
The valve can be oriented in any direction, there is no gravitational influence to worry about. They are very reliable.

That's what I suspected, thanks for confirming.

It tempers the outgoing water, but is not anti-scald. Always add a thermometer to the installation to allow for accurate adjustments.
The ASSE 1017 standard states that when used, "They should be supplemented by a point of use device to control final temp to fixture".
In other words, you should have an anti-scald shower valve, which all modern pressure balancing or thermostatic shower valves have.
As far as faucets, in residential settings, the additional protection is not legally required and virtually never done.

So you're saying this protection might be built into my existing shower valves ? How can I tell ?

The literature for the valve (I've already purchased) seems to say it IS anti-scald, including the sentence "Designed to prevent scalding water and legionella bacteria growth by storing water at 140° F and higher, but delivering safe and comfortable water temperatures out of the faucet up to 120° F."

am-1-series-02.jpg
 

Attachments

  • 03-00367.pdf
    1.1 MB · Views: 27
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks