Water temp not matching water heater

[Ercove21]

So I just installed an AO Smith signature select 50 gal electric 5500.model E940R55DV110. It has an Apollo MVBLF mixer on it and piped in with PEX. Running 10-2 MC to it on a 30 double. I have turned the thermostats on the unit up to about 130-135 and got “hot” no steam water. I made sure the lower was higher than the upper also. I then opened it up all way on the mixer, counter clockwise, for hot water and took a shower after about an hour. When the water was turned all the way up, all the way, it was what some would call a hot shower. If I turned it down to where it used to burn the hell out of me it was now warm, bordering cold. A couple days ago my 15 year old GE unit went so we had to replace with this one. It had no issue with making water hot enough to skin a cat so we got used to hot water in our house. I waited about an hour after bathing and got a cup, let the water run full hot and temp checked it with 4 different thermometers ( don’t ask why I have that many lol) all read 106 degrees. That is lower, much lower than what the thermostat is set at. This unit was installed at 3pm est and all of this took place up until this morning post. I checked both elements for continuity and beep beep they are good. Can anyone suggest why not hot water isn’t peeling my skin on full bore all of a sudden...and what I can do to fix? It s so frustrating!!!!

 

[Reach4]

I then opened it up all way on the mixer, counter clockwise, for hot water and took a shower after about an hour.

Even with the mixer turnded max hot, it still may be mixing in a lot of cold.

Those non-contact IR thermometers with the laser pointer are nice.

If you point at the pipes into and out of the mixer, I suspect that will tell the story.

Or maybe you could touch quickly with a finger to check relative temperatures.

 

[Sponsor]

 

[Ercove21]

Even with the mixer turnded max hot, it still may be mixing in a lot of cold.

Those non-contact IR thermometers with the laser pointer are nice.

If you point at the pipes into and out of the mixer, I suspect that will tell the story.

Or maybe you could touch quickly with a finger to check relative temperatures.

I can grab the pipes all the way through. They are warm but not burn level. The outlet (hot) connection, is very hot on the fitting but after the mixer, it’s mediocre. Where should I start problem solving. With the thermometers, one of mine is the one I use for sugar work, used to use digital but they are inaccurate and things began to burn. So I am asking the boards, where do I start with this troubleshoot? Thanks!

 

[Bannerman]

An electric water heater will likely require considerably more than 1 hr to raise 50 gallons of cold water to 135F.

In addition, I suspect the thermostats are simply not accurate and are calibrated vastly different to your previous heater. You might try a 165 F setting to determine if that will satisfy your requirements.

As the hottest water will rise to the top of the tank, a slightly higher temperature setting for the upper element should improve the hot water recovery time as the upper element will then further supplement the heat produced by the lower element.

If all of the hot water is flowing directly to the mixing valve, running a higher tank temperature should not be a concern and will provide additional hot water capacity. Maintaining an internal temperature above 140F all the way to the bottom of the tank will prevent bacteria which can develop at lower temperatures.

If you do wish to utilize a laser pointer digital thermometer to measure the temperature entering the mixing valve, either wrap some tape around the copper pipe/fitting where the laser will be pointed at or, paint that section. This will improve the reading accuracy of a digital non-contact thermometer when measuring the temperature of a metal pipe.

 

[Reach4]

I can grab the pipes all the way through. They are warm but not burn level. The outlet (hot) connection, is very hot on the fitting but after the mixer, it’s mediocre. Where should I start problem solving. With the thermometers, one of mine is the one I use for sugar work, used to use digital but they are inaccurate and things began to burn. So I am asking the boards, where do I start with this troubleshoot? Thanks!

Your descriptions make it clear that your mixer has an upper-limit on its range, and you cannot adjust it enough to let all-hot water through. In other words, your mixer is maxed out in its temperature adjustment. Is that by design? I don't know. What do the specifications say?

I am not a pro, and I have never had one of those mixers.

 

[Ercove21]

Reach4, Thank you for your response. It makes a lot of sense and at the same time it doesn't. Why would I only be allowed to get out 100 degree water at max????

https://api.ferguson.com/dar-step-s...3102&USE_TYPE=INSTALLATION&PRODUCT_ID=7600865

That's the link for my mixer.

Attached is an image of the unit as it is now.

after that M (mix) that water pipe is lukewarm at best. that hot water on off however is hot enough to burn if left for a while.

If I were to replace this, what tools would I need and what would be the steps? Thanks!

 

[Fitter30]

Electric water heaters top element heats bottom is off till top t stat satisfied then power is sent to bottom t stat.
Mixing valve could be sticking from the minerals in the water heres the install manual and has numbers in it for build kit.
https://www.google.com/url?q=https:...FjAAegQICxAB&usg=AOvVaw1G99RC7LEWDWjz7uPAd34v

 

[Reach4]

Reach4, Thank you for your response. It makes a lot of sense and at the same time it doesn't. Why would I only be allowed to get out 100 degree water at max????

https://api.ferguson.com/dar-step-s...3102&USE_TYPE=INSTALLATION&PRODUCT_ID=7600865

That's the link for my mixer.

That link says there is a limit stop. I expect that stop has been set to too low of a temperature. The document says there is a set screw.

http://www.apollovalves.company/catalogs/Apollo_Mixing_Valve_Catelog.pdf says model 34A has an adjustable limit stop, but it does not say that for 34B.

If your unit does not have a limit adjustment, and cannot reach 120 degrees, then I would say it is defective, and seek a warranty replacement or repair. I am not a pro.

 

[Ercove21]

Electric water heaters top element heats bottom is off till top t stat satisfied then power is sent to bottom t stat.
Mixing valve could be sticking from the minerals in the water heres the install manual and has numbers in it for build kit.
https://www.google.com/url?q=https://api.ferguson.com/dar-step-service/Query?ASSET_ID=2969474&USE_TYPE=INSTALLATION&PRODUCT_ID=4631096&sa=U&ved=2ahUKEwjfwcCgprLtAhVXZc0KHX3_CHUQFjAAegQICxAB&usg=AOvVaw1G99RC7LEWDWjz7uPAd34v

This water heater is brand new, no time for minerals yet....Right?????

 

[Ercove21]

That link says there is a limit stop. I expect that stop has been set to too low of a temperature. The document says there is a set screw.

http://www.apollovalves.company/catalogs/Apollo_Mixing_Valve_Catelog.pdf says model 34A has an adjustable limit stop, but it does not say that for 34B.

If your unit does not have a limit adjustment, and cannot reach 120 degrees, then I would say it is defective, and seek a warranty replacement or repair. I am not a pro.

Can we get a professional to respond to this?!>?!>! I think you are right but I need a pro to weigh in!!!!!

 

[Ercove21]

So I am wondering now If I replace with one with an operating temp between 85 and 145 if the problem will be solved. Also trying to get a quote for someone to replace it.....

 

[Bannerman]

This water heater is brand new, no time for minerals yet

Fitter30 was referring to mineral buildup in the mixing valve. You mentioned the WH is new but didn't specify the age of the mixing valve.

Have you followed the instructions for setting the temperature limit on the mixing valve? That is performed with the adjustment knob removed to access the limit adjustment below.

https://api.ferguson.com/dar-step-s...3102&USE_TYPE=INSTALLATION&PRODUCT_ID=7600865

 

[Ercove21]

Fitter30 was referring to mineral buildup in the mixing valve. You mentioned the WH is new but didn't specify the age of the mixing valve.

Have you followed the instructions for setting the temperature limit on the mixing valve? That is performed with the adjustment knob removed to access the limit adjustment below.

https://api.ferguson.com/dar-step-s...3102&USE_TYPE=INSTALLATION&PRODUCT_ID=7600865

I apologize!, yes everything is brand new. I undid the screw on the top and spun the plastic cap counter clockwise until it stopped. This in theory opens it up full. I didnt use any allen wrenches, just the plastic cap I will look more into it tonight.

 

[Fitter30]

Water heater has to be a minimum of135* for mixing valve 120* which is the highest temp setting

 

[Jadnashua]

You need to calibrate things by doing the adjustment screw limit stop procedure listed in the instructions. Code says that except for certain applications (like a dishwasher or washing machine), the mixed outlet water temperature cannot exceed 120-degrees F, but until it is calibrated, there's no guarantee the adjustment knob will be right. Some brands come calibrated better.

If I read it correctly, you said the hot going into the mixer was quite hot. At max outlet of the mixer set to 120-degrees per code, they also say the minimum inlet temp from the tank would need to be 135 (15-degrees higher, minimum). So, if the inlet IS 135, and you can't get the 120 out when adjusted to max, you need to calibrate it. Then, if that doesn't work, you'd need to replace it with a working one.

Once you get all of this resolved, you should reset the max temp on your shower valve itself. If you had a thermostaically controlled one, it should not be necessary, but on a typical pressure-balanced valve, you should. And, if you wanted to be perfectly correct about it, you should readjust it in the spring/summer once the ground water warms up again. If you've adjusted it properly in the winter, it would end up too hot