water heater adjustable thermostat

[Beaker]

I'm thinking of replacing thermostat on water heater with an adjustable one. This sucker is way too hot!

Replacement looks pretty simple on youtube.
Has anyone replaced theirs, have reasons not to, or run into any problems?

[tpi]

If you replace with adjustable, be sure the upper range of adjustment is at least the equal of what it is now. On cold winter days, that hot water is a big plus when you're mixing with 40 degree fresh water, loss of heat in the pipes, and possibly a cold you. Between desert summers, and cold winters there is a big difference how long a shower can last.

[Colo_Native]

I replaced mine and set to the lowest setting plenty of hot water easy to do and I got it off Amazon for about $28

[mlts22]

+1 for a mixing valve. The higher temperatures also help with killing bacteria which might have formed when the tank was cool.

[Old-Biscuit]

Golden_HVAC wrote:
Yep - they set them for 140F because you can mix about 6 gallons of incoming 55F water and still have 12 gallons of 100F water to shower or wash dishes.

If lowered to 120F, then you can only mix in about 3 gallons of cold water, and you will only have 9 total before running out hot water.

Another brand of water heater sets the thermostat even higher, like 160F. THen they MUST use a water mixing valve, so the output is limited to a max 120F, to prevent scalding, and basically the first gallon of hot water is mixed with nearly 1 gallon of cold water, so the 6 gallons last for about 12 output at 120F.

It gives a lot more hot water, and the mixing valve prevents the scalding.

My suggestion is to get a mixing valve. Then you can still have the full output, and not get scalded.

Fred.

That would be Atwood XT models.....6 gallon & 10 gallon sizes.
T-stat set for 160*F and mixing valve output set for 130*F which still requires mixing with cold at point of use.
Equivalent of 9 gallon (from 6 gallon size tank) and 12 gallon (from 10 gallon size tank)

[Beaker]

My suggestion is to get a mixing valve. Then you can still have the full output, and not get scalded.

I will look into this. No reason to have water as hot as this.

[Golden_HVAC]

Yep - they set them for 140F because you can mix about 6 gallons of incoming 55F water and still have 12 gallons of 100F water to shower or wash dishes.

If lowered to 120F, then you can only mix in about 3 gallons of cold water, and you will only have 9 total before running out hot water.

Another brand of water heater sets the thermostat even higher, like 160F. THen they MUST use a water mixing valve, so the output is limited to a max 120F, to prevent scalding, and basically the first gallon of hot water is mixed with nearly 1 gallon of cold water, so the 6 gallons last for about 12 output at 120F.

It gives a lot more hot water, and the mixing valve prevents the scalding.

My suggestion is to get a mixing valve. Then you can still have the full output, and not get scalded.

Fred.

[Old-Biscuit]

If you have an Atwood WH.......there is an aftermarket adjustable t-stat that will replace the normal t-stat (normal preset for 140*F----adjustable 110*F-150*F)

The adjustable uses a three-legged bracket that holds t-stat in place.
I found the bracket to be a bit flimsy, the size of adjustable w/bracket does not lend itself to being covered with insulating foam so it is more exposed to outside elements and if PRV should drip it does so directly onto t-stat.

It does control to temps on setting fairly well.....but when using temps lower than factory preset.......you find yourself using more hot water vs mixing with cold to achieve usable temp at faucet.


Suburban does not have an adjustable t-stat........but if you have propane only a household WH adjustable t-stat can be 'modified' for use.


But reason pre-set t-stats are used is to make hot water for mixing with cold for usable temp at faucet with a small, light weight WH.
Remember it is an RV........

[ScottG]

dahkota wrote:
One of the reasons the water is so hot is so it will last longer - you need to mix it with more cold than hot, making 6 or 10 gallons last at least long enough for a shower.

Exactly, other than washing dishes or hands the WH will be useless if you reduce its heating ability.

[dahkota]

One of the reasons the water is so hot is so it will last longer - you need to mix it with more cold than hot, making 6 or 10 gallons last at least long enough for a shower.