Heater Problem in a Church Baptistry

[Little Bill]

I was asked to do a few things at a Church. It was mainly just a quick look at adding some lights and replacing a switch. After I looked at the things and was about to leave, the guy asked if when I came to do the work if I could check their baptistry to see why the heater for the tub kept tripping. I asked if the GFCI was tripping and he said yes. So I started to check the GFCI breaker to see if it held with no load on it. It stayed on and I told him if it was tripping there was something wrong with the heater. He said that it was not the breaker that tripped but they had to hit the reset button on the heater box.
I didn't have time to check anything on it but said I would look into it when I did the other jobs.
My question is, what would cause the heater to have to be reset and not trip the GFCI breaker? He said that when they use the baptistry, they keep the thermostat set to "high".
What is the heater unit sensing that causes it to shut off and need resetting? I know little to nothing about how they work, but I'm guessing it's a high temperature shut-off. Maybe the thermostat is sticking and causing it to overheat.
I just need to know what to look for when I check it. If anyone can help with this, I would appreciate it.

 

[iwire]

Just a guess that they keep draining the baptistery without shutting the heater off first.

Or the regular thermstat is allowing it to run too hot. It is not supposed to be a spa.

 

[iwire]

Not to scare you but keep in mind a minister was electrocuted in front of the congregation from a faulty heater.


http://www.churchsafety.com/articles/2010/baptisterysafety.html

 

[augie47]

My limited experience coincides with I-wire's post.
I have seen one arrangement that had a water sensing circuit that opened a relay if the heater switch was "on" and the water level was low.
I have also seen the second scenario when the primary thermostat was bad.
I probably need not tell you, the clue will be in what role the "reset" button plays.

 

[kwired]

Bob is correct that it is not supposed to be a spa. But it probably has a lot of similarities to a spa.

A spa heater usually has pressure switch to prove water flow before allowing heater to run.

High limit is kind of a back up in case the pressure switch should fail or for some reason there is pressure and not enough flow.

If it is a heater like most spas have it will overheat quickly if water is not flowing. You might want to make sure it is not heating for some reason when the pump is not running.

 

[augie47]

Bob is correct that it is not supposed to be a spa. But it probably has a lot of similarities to a spa.

A spa heater usually has pressure switch to prove water flow before allowing heater to run.

High limit is kind of a back up in case the pressure switch should fail or for some reason there is pressure and not enough flow.

If it is a heater like most spas have it will overheat quickly if water is not flowing. You might want to make sure it is not heating for some reason when the pump is not running.

pump ???? wow ! You deal with a higher class clientele
The baptistery units I've worked on are just one step above a enclosed wash tub

 

[iwire]

Bob is correct that it is not supposed to be a spa. But it probably has a lot of similarities to a spa.

A spa heater usually has pressure switch to prove water flow before allowing heater to run.

High limit is kind of a back up in case the pressure switch should fail or for some reason there is pressure and not enough flow.

If it is a heater like most spas have it will overheat quickly if water is not flowing. You might want to make sure it is not heating for some reason when the pump is not running.

I was sent to a home to do a 'favor call' for a person important to the company.

Anyway they had a very large hot / spa / jacuzzi thing on the second floor off of the master bath. I was sent out because for many years each time the person wanted to use it they went to the basement and pushed the reset button on the gas fired pool heater being used to heat this thing. Other than that I had no info.

So I go downstairs hit the reset button the unit fires right up, in no time the thing starts making very scary noises and is practically jumping off the floor, it was boiling the water in it.

To shorten it up I tracked it down to a jumped out flow switch in the plumbing that was installed in the wrong direction so apparently it had been this way since it was installed.

 

[kwired]

pump ???? wow ! You deal with a higher class clientele
The baptistery units I've worked on are just one step above a enclosed wash tub

I have no idea what a heated baptistery is - I guess I was assuming those were larger water bodies so that people actually get in the water just like John the Baptist was in the river and people came into the river to be baptized. All churches I have ever been to use what you could call a bowl of water and it is at room temperature. If you wanted it warm why not heat the water before placing it in the bowl? Not trying to get into religuious practices here but understanding why things are done does help understand the needs.

 

[stevebea]

I have no idea what a heated baptistery is - I guess I was assuming those were larger water bodies so that people actually get in the water just like John the Baptist was in the river and people came into the river to be baptized. All churches I have ever been to use what you could call a bowl of water and it is at room temperature. If you wanted it warm why not heat the water before placing it in the bowl? Not trying to get into religuious practices here but understanding why things are done does help understand the needs.

Every bapistry I have seen is about twice the size of a hot tub. Enough room for the minister and the person being baptized to kneel and enough room to dip them front or back depending on the notion of which is the correct way to dip.

 

[iwire]

What I have seen the few times in a church

 

[Little Bill]

The baptistry does have a pump. There is wiring from the disconnect to the heater than to the pump. I assume there is some sort of flow/pressure switch that won't allow the heater to run "dry". The guy did say they kept the breaker turned off when draining or not in use.
I believe he said the problem was when the tub was full and they went to check on the temp. of the water, they would find the reset button tripped on the heater box.
That is why I was thinking the thermostat was not working correctly and letting the heater get too hot.
But that's just my uneducated guess!

 

[hillbilly1]

Could be a low flow problem, the flow switch just verifies flow, but not how much. A restriction could cause the water to get to hot in the tube tripping the hi limit. I would look for a clogged intake. Probably hair.

 

[iwire]

Probably hair.

But a darn good suggestion none the less.

 

[Little Bill]

Could be a low flow problem, the flow switch just verifies flow, but not how much. A restriction could cause the water to get to hot in the tube tripping the hi limit. I would look for a clogged intake. Probably hair.

Thanks, I'll check on that when I go back.

But a darn good suggestion none the less.

I might even find enough hair to make a wig & sell it!:thumbsup::lol:

 

[ceb58]

What I have seen the few times in a church

That one is identical to the one I just wired a few weeks ago.
There should be a switch that when turned on should open a valve to fill the tub. When it is full it will shut off the flow and turn on the circulating pump and heater. The heater wiring goes through a relay and should not let the heater come on as long as it is filling. Sounds like the pump is not coming on and the heater is going out on high temp.

 

[Little Bill]

That one is identical to the one I just wired a few weeks ago.
There should be a switch that when turned on should open a valve to fill the tub. When it is full it will shut off the flow and turn on the circulating pump and heater. The heater wiring goes through a relay and should not let the heater come on as long as it is filling. Sounds like the pump is not coming on and the heater is going out on high temp.

I think they manually open a valve to fill the tub. I didn't see a relay unless it is in the heater box. It is about the size of a single gang box. The guy said they left the breakers (1 for the pump and 1 for the heater) off until the tub filled.
I could be wrong as I only took a quick look and was going by what he said as to their procedure.
I may have to actually watch them fill the tub and see what happens, but keep the suggestions coming!

 

[kwired]

The baptistry does have a pump. There is wiring from the disconnect to the heater than to the pump. I assume there is some sort of flow/pressure switch that won't allow the heater to run "dry". The guy did say they kept the breaker turned off when draining or not in use.
I believe he said the problem was when the tub was full and they went to check on the temp. of the water, they would find the reset button tripped on the heater box.
That is why I was thinking the thermostat was not working correctly and letting the heater get too hot.
But that's just my uneducated guess!

What you don't know is how long it operated before tripping, and what may have been happening at the time it tripped.

Maybe proof of flow (likely a pressure switch) doesn't open and for some reason flow either stops or is restricted enough that high limit is called upon.

Scenario that could be likely - pressure switch has been stuck in closed position for who knows how long (make sure it opens when there is no pressure), pump has an overload condition with internal automatic reset (very likely with this kind of motor) and stops running when overload opens motor circuit, because pressure switch doesn't work heater continues to heat - takes very little time for high limit to open shutting down the entire unit.

By the time it is discovered motor has cooled and runs again when high limit is reset. Motor could have always been overloaded (design problem?) and normal operation would resume when motor overload automatically resets, but now the pressure switch has stuck and made it so it continues to heat when motor stops.

 

[Little Bill]

What you don't know is how long it operated before tripping, and what may have been happening at the time it tripped.

Maybe proof of flow (likely a pressure switch) doesn't open and for some reason flow either stops or is restricted enough that high limit is called upon.

Scenario that could be likely - pressure switch has been stuck in closed position for who knows how long (make sure it opens when there is no pressure), pump has an overload condition with internal automatic reset (very likely with this kind of motor) and stops running when overload opens motor circuit, because pressure switch doesn't work heater continues to heat - takes very little time for high limit to open shutting down the entire unit.

By the time it is discovered motor has cooled and runs again when high limit is reset. Motor could have always been overloaded (design problem?) and normal operation would resume when motor overload automatically resets, but now the pressure switch has stuck and made it so it continues to heat when motor stops.

I wish I had of had more time to look at things when I was there. But as I said, this was a "while you are here" type thing and I was ready to leave when this came up.
I didn't think to ask him if the pump was running when they have to reset the heater.
I will see if I can get in touch with him to question him more before I go back as he won't be there when I do the other work. That might make things easier when I go to troubleshoot it.

 

[kwired]

I wish I had of had more time to look at things when I was there. But as I said, this was a "while you are here" type thing and I was ready to leave when this came up.
I didn't think to ask him if the pump was running when they have to reset the heater.
I will see if I can get in touch with him to question him more before I go back as he won't be there when I do the other work. That might make things easier when I go to troubleshoot it.

Chances are if high limit trips it shuts down everything. Pump starts when they do reset it because it has cooled down by then - that is if the problem is my scenario or anythign close to it.

 

[ceb58]

If you find that it is a Little Giant system and it dose have a elect. fill valve check the wiring on the switch. The instructions show one of the terminals as N/O when it is in fact N/C. Found all this out the hard way when things did not work as should. I called their tech. support to question them on this and they admitted there was a typo on the instructions. The new instructions had been corrected and they would put them in after they used up the wrong ones :?