Statesman 30 Gallon Commercial Electric help!

[Joel6211]

I am going to track down a new thermostat and hopefully provide a happy update in a day or two. If I turn it up more to t displays the same behavior, ie warms for a few minutes then trips at the contactor.

WH is in a non for profit elementary school environment and has a pretty elaborate mixing valve system/manifold in place to insure the kids are safe regardless of what the WH is producing.

Totally appreciate the guidance thus far. Joel

 

[Joel6211]

Well just installed new thermostat and no change in “behavior”. Water heater comes on for 3-5 minutes. Gets them temp to around 95, then breaker button in contactor trips.

So does this point to the contactor as suspect?

 

[Sponsor]

 

[Reach4]

Well just installed new thermostat and no change in “behavior”. Water heater comes on for 3-5 minutes. Gets them temp to around 95, then breaker button in contactor trips.

So does this point to the contactor as suspect?

Check the voltage on the contactor control input. If the 120 VAC stays but the contactor opens, it is the contactor. If the 120 volts goes away, then the contactor is doing its job by shutting off. I am betting the problem is not the contactor. I would like to be wrong.

I don't know if a broken dip tube could cause this. The dip tube's job is to bring the cold water to the bottom of the heater usually. It may be that without the dip tube directing flow, the cool water is not flowing by the thermostat, and the thermostat sees warmer water.

 

[Joel6211]

Check the voltage on the contactor control input. If the 120 VAC stays but the contactor opens, it is the contactor. If the 120 volts goes away, then the contactor is doing its job by shutting off. I am betting the problem is not the contactor. I would like to be wrong.

I don't know if a broken dip tube could cause this. The dip tube's job is to bring the cold water to the bottom of the heater usually. It may be that without the dip tube directing flow, the cool water is not flowing by the thermostat, and the thermostat sees warmer water.

Thanks I will have to check the voltage on the contactor.

The cold water inlet is located almost at the bottom of the tank so guessing a dip tube issue might not be in play for this unit.

 

[Joel6211]

Help me clarify my thinking. Learning fast about contractors. The “trip” at the contactor I have described is likely just power exiting the contactor. The button “pulls in” when power enters, draws coil down and makes “contact”.

Could a faulty high limit switch be part of the problem?

 

[Reach4]

Could a faulty high limit switch be part of the problem?

Sure. That should be detectable by probing. Use a terminal connected to the white wire as a reference for one meter probe or use a terminal hooked to the green wire. You could use an alligator clip to grab a terminal up top where the two green wires come together. WIth the other probe, probe the top and bottom terminals of the thermostat. If the bottom shows 120v and the top shows zero, then it is the thermostat telling the WH to shut down. If the bottom terminal has no voltage, then you can suspect the high limit switch or an intermittent fuse, or something else.

I think the high limit switch is that the thing with the red button. If so, that may stay tripped once tripped, and require pressing the button to restart the WH.

 

[Joel6211]

With power on and voltage flowing through the contactor there isn’t any current present in the white wire. Should there be? What is white wire purpose? Goes from bottom side of contactor to transformer.

With power on, I verified voltage to, through thermostat and across the high limit switch with non contact probe. This is starting to make me crazy.

 

[Reach4]

With power on and voltage flowing through the contactor there isn’t any current present in the white wire. Should there be? What is white wire purpose? Goes from bottom side of contactor to transformer.

There should be a small current, but it may be too small to notice on your clamp-around ammeter. The current through the white wire will be the same as the current through each of the wires on the thermostat.

If we compare electric to water pipes, voltage is like psi. Current (measured in amps or milliamps) is like gpm.

 

[Joel6211]

There should be a small current, but it may be too small to notice on your clamp-around ammeter. The current through the white wire will be the same as the current through each of the wires on the thermostat.

If we compare electric to water pipes, voltage is like psi. Current (measured in amps or milliamps) is like gpm.

Thanks. Can’t measure at thermostat, but non contact probe says they are energized.

No power present at White.

 

[Ladiesman217]

Set your voltmeter to the AC voltage scale.

Connect one meter lead to the white wire that goes to the contactor.

Connect the other meter lead to the black wire that goes to the contactor from the thermostat.

1. Measure the voltage when the thermostat calls for heat.

2. Measure the voltage when the thermostat does not call for heat.

3. Measure the voltage after the water temperature gets as high as it can get the way things work now.

That should tell you what to do next.

 

[Reach4]

Thanks. Can’t measure at thermostat, but non contact probe says they are energized.

No power present at White.

Normal for your non-contact probe. That device is roughly measuring the voltage between the conductor probed and your hand. Your hand is approximately at ground level, and the white wire is at ground level. So no light on your probe.

Your probe can be handy to see where the path of the voltage to the contactor coil is getting stopped. Expect the bottom terminal of the thermostat to always light your probe. Expect the top terminal of the thermostat to light your probe only when the thermostat is calling for heat.

 

[Joel6211]

Set your voltmeter to the AC voltage scale.

Connect one meter lead to the white wire that goes to the contactor.

Connect the other meter lead to the black wire that goes to the contactor from the thermostat.

1. Measure the voltage when the thermostat calls for heat.

2. Measure the voltage when the thermostat does not call for heat.

3. Measure the voltage after the water temperature gets as high as it can get the way things work now.

That should tell you what to do next.

127 for scenario #1, 0 for #2 and 127 for #3 (right before contactor loses “contact”

 

[Ladiesman217]

I assume that for scenario 3 that after the contactor loses "contact" the voltage drops to around 0 VAC. If that is correct, the contactor is working.

Assuming that I have read the schematic diagram for the correct model, the 127 VAC control circuit goes from the transformer output through a fuse through the high limit switch through the thermostat to the contactor.

Check for 127 VAC after the contactor drops out. One volt meter lead on white. Second volt meter lead on:

1. Fuse in from transformer

2. Fuse out to high limit switch

3. High limit switch input

4. High limit switch output

5. Thermostat input

6. Thermostat output

7. Contactor input

Once the contactor drops out, find out where you lose the 127 VAC contactor control voltage.

Since you installed a new "good" thermostat, I suspect that the high limit safety switch is going to be where the 127 VAC control voltage drops out.

In a good circuit the thermostat input voltage should be a constant 127 VAC at all times. The thermostat output voltage should cycle between heat on (127 VAC) and heat off (0 VAC).

 

[Joel6211]

I see voltage at all suggested contact points with the exception of the two contact points highlighted. No voltage measured, but get a “beep” from my voltage meter.

 

[Reach4]

Thermostat is cutting you off for sure.

Is one of the heating elements close to the sensor for the thermostat? The obvious question is, if that is a problem now, why was it not a problem for the first 30 years? And even if that was somehow the problem, why would the water not eventually get to full hotness with enough cycling?

If you decided that could explain things, maybe you could de-power that element, and work with two elements heating as a workaround. It would be trial and error to find the right wire I think.

 

[Ladiesman217]

The thermostat is cycling on and off as designed. Call for heat 127 VAC, temperature satisfied 0 VAC.

Are you positive of the water temperature in the tank? Where do you measure the temperature of the hot water? At the tank?

You can turn up the temperature on the thermostat dial if the water temperature in the tank is actually a steady 95° F.


If you have a tempering valve installed in the system, it could be bad.

https://terrylove.com/forums/index....c-mixing-valves-water-heater-tempering.45651/


Do you have a picture of the plumbing on the output side of the water heater?

 

[Joel6211]

So I think I verified that my WH is now working fine and that the problem is in the Symmons TempControl system. Private elementary school environment.

Shutting off the cold water inflow to the temp control manifold system, I was able to get 135 degree water at the tap.

With cold water inlet open, them temp at the tap maxes about 98. I turned both temp dials all the way to cold and it only pushed the tap temp to about 90 degrees.

Is there a cartridge in these that can go bad? Or scale build up that needs to be cleaned?

 

[Ladiesman217]

View attachment 45517

So I think I verified that my WH is now working fine and that the problem is in the Symmons TempControl system. Private elementary school environment.

Shutting off the cold water inflow to the temp control manifold system, I was able to get 135 degree water at the tap.

With cold water inlet open, them temp at the tap maxes about 98. I turned both temp dials all the way to cold and it only pushed the tap temp to about 90 degrees.

Is there a cartridge in these that can go bad? Or scale build up that needs to be cleaned?

What happens if you set the temp dials to hot instead of cold?

This may be of help. There is a link to the installation instructions.

https://www.symmons.com/products/tempcontrol-valve-7-900/

 

[Joel6211]

What happens if you set the temp dials to hot instead of cold?

This may be of help. There is a link to the installation instructions.
https://www.symmons.com/products/tempcontrol-valve-7-900/

Literally no change when I crank the dials to hot (far as I can go) from cold (far as I can go). Maybe 5 degrees difference.

 

[Ladiesman217]

At least your water heater has been cleaned up and is working properly.

You could boost the water heater temperature up by 10° F and see how the tempered hot water measures. As long as the final tempered hot water temperature is reasonable that may be where you should start.

There is a thermostatic cartridge that goes in each Symmons valve. The maintenance instructions are on page 10 and 11. The maintenance instructions say to keep spares on site for service. Perhaps the cartridges are going bad and need to be replaced.

Do you think that you have the skill level to change them? It takes time to learn how to do things right. Instructions below.

The diagram 4 on page 9 may apply to your setup. You have to confirm that pipe routing.

Depending how old that system is, you could have series 5, 6 or 7. Are there any instructions on site? You can call Symmons to find out if all the cartridges are interchangeable.

You will find that Symmons parts are really, really expensive. You have to order the exact part number, no guessing. On the bright side, Symmons keep repair parts availability for a long time.


Maybe you should look for a plumber with commercial valve experience. I have no history with this setup.