Mastertemp Heater Igniter Resistance?

Jump to latest Follow Reply
In your video you removed the plug for the pressure relief valve and I would expect waster to be in there as it is actually draining it from the system. You needed to remove the bottom manifold bolt, you should have 10 total bolts, 5 on each side of the manifold in the front of the heater. Sort of right next to the pressure relief plug. You will always get water out of where the relief valve goes.

If the when the bottom manifold bolt is removed, if you get water coming out, then you have a leak in the tube sheet. Leaks/holes in the tube sheet is from improper chemical balances in your water.
 
racket said:
Put a multimeter on the FC terminals on the Fenwal control it should read more than 3.0VDC when the heater is fired. If its less , you might need to ground the flame holder.

http://www.pentairpool.com/pdfs/MTMETGrdwirekit.pdf
Click to expand...

I fired up the heater and set my multimeter to 10VDC.

I'm not super comfortable with the multimeter (getting better)...so I'll describe what I did.
1. Set my multimeter to 10vdc
2. The black scale (10 to the far right) just above the red scale (see picture of my multimeter in previous post in this thread) read .75VDC. So nowhere near 3.0VDC.

I googled the pentair part number....and found nowhere to buy the part online.

Where can I get this? Or...is there something comparable that I can use? Perhaps something like this: http://www.homedepot.com/p/Ideal-Green-12-AWG-Solid-Pigtail-with-Screw-50-Pack-30-3392R/202894316?

Just wondering what kind/gauge wire I need to use.

Thanks
 
ps0303 said:
In your video you removed the plug for the pressure relief valve and I would expect waster to be in there as it is actually draining it from the system. You needed to remove the bottom manifold bolt, you should have 10 total bolts, 5 on each side of the manifold in the front of the heater. Sort of right next to the pressure relief plug. You will always get water out of where the relief valve goes.

If the when the bottom manifold bolt is removed, if you get water coming out, then you have a leak in the tube sheet. Leaks/holes in the tube sheet is from improper chemical balances in your water.
Click to expand...

Thanks for the info. I give as much info as possible in case I mess up....like removing the wrong bolt!!!
I think that I removed the correct bolt....and thankfully....no water came out.
Here is the video: https://www.youtube.com/watch?v=a5CkyTD-pxg

Thanks for you help.
 
No luck so far.

Short Version: Does the stripped end of the ground go on the bottom or top of the "bottom gasket"?

Long Version:

I installed the ground. I then fired up the heater (7th straight time in a row that it fires "when cold") and checked the voltage across the FC on the Fenwall. It was exactly the same....about .75 vdc???

Here are some pictures:
HeaterGroundInstallation.jpg
HeaterGroundUnderGasket.jpg

Maybe I installed it incorrectly. I placed the stripped end of the ground wire underneath the bottom gasket. I wasn't sure. The instructions use the terms "flame holder plate" and then just "flame holder".....as in "insert a flat blade screwdriver between the bottom gasket and the flame holder". The user manual lists parts: Flameholder/Adapter Plate Gasket, Flameholder Assembly, and Flameholder/Combustion Chamber Gasket. I'm assuming the "Flameholder/Combustion Chamber Gasket" is what is referred to in the instructions as the "bottom gasket".

So why do the instructions make use of "flame holder plate" and "flame holder" when the only metal piece is the "Flameholder Assembly"? The instructions sort of make it sound like the ground wire should go on top of the gasket. But then I thought, "The flameholder assembly is sandwiched between two gaskets, so it needs a path to ground....and... It doesn't make sense to have the ground attached to the bottom of the plate (top of gasket) and the top of the plate - screwed down on weld stud."

So I concluded the ground goes on the bottom of the gasket. If this is incorrect, that would explain why the FC voltage remained well below 3.0vdc.

Thanks for your help.
 
Last edited:
The directions imply to have the wire between the holder and the gasket. So you have flame holder, gasket, can. "Slide the ground wire with strip end between flame holder and bottom gasket" So you would have flame holder, stripped end of wire, gasket, can.
 
OK. I changed the ground from below the bottom gasket to the top. So it is between the flame holder and bottom gasket.
HeaterGroundOverGasket.jpg

Unfortunately, it doesn't appear to have had any affect.

My problem persists.

I fired up the heater (8th time in a row that it fire "when cold"). I checked the voltage on the FC of the Fenwall.....still about .75vdc.

After temperature (78F) was reached and the heater was quite, I increased the temperature to 83. Heater failed to ignite.

The fan comes on....I hear a click....I smell gas....and nothing.

I'm puzzled why the FC voltage never changed.
I used 16 gauge landscape wire with a loop crimp connector to slip over the welded stud.

Any other ideas?
 
No, I didn't.

The directions state: "The ground wire can be installed in either of two locations"

I can run a second ground wire into the control box.

Do you think running the ground into the control box is a better fix?

Or do techs usually run two grounds to fix this problem?

Thanks for your help.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Honestly, I didn't read any of the doc. I think its kind of a joke that they want you to do this in the first place. If adding the second doesn't work, call Pentair. I'm not sure what the problem is with your heater but I'd shoot the dam thing if it were mine.
 
The terminal needs to make contact with the burner cup.
The reason for this "update" I think is because pentair coated the top of the combustion chamber which isn't conducive for a good ground.

If the FC didn't change at all, replace the ignitor..
 
Pool Clown said:
Uncharacteristic of you Paul... Everything alright???
Click to expand...

Yeah I know. LOL

- - - Updated - - -

racket said:
The terminal needs to make contact with the burner cup.
The reason for this "update" I think is because pentair coated the top of the combustion chamber which isn't conducive for a good ground.

If the FC didn't change at all, replace the ignitor..
Click to expand...

The ignitor was already replaced. He posted it in an earlier post.
 
ps0303 said:
Many posts back Pool Clown suggested replacing the Fenwal ignition module. I would suggest that as a next move at this point. Seeing as you don't have a spare now you need to purchase one. Find a place to buy it from that you could return if it doesn't solve your problem.

http://www.amazon.com/Pentair-42001-0052S-Electrical-Systems-Replacement/dp/B003ANKIUG
Click to expand...

I also suggested hiring a guy to diagnose this. If it turns out that it isnt the Fenwal, at least you are not out the cost, but either way you will have to pay the labor. On the other hand, you may be able to make an agreement with him that you pay only if it is fixed. I good tech would be more likely to agree to this if he were confident (and experienced enough) that he could fix the heater. This agreement could be a good way to "weed out" the hack techs.

Good luck returning an electrical component, most places wont accept returns of these (i know i don't). Mainly because you cant tell if it has been damaged.
 
So I added the second ground.

HeaterGroundStripLeads.jpg
HeaterGroundLocation2.jpg

So I fired it up (9th time cold fire in a row).
Still get .8vdc from FC when it is fired.

....and voila....it ignited when it called for more heat. So I'm all happy. I get the wife and some beers and have a nice soak in the spillover spa to celebrate. The heater came on 5 times during the soak. Worked perfectly!!!

So this morning, I decide that I'm going to "prove" that it was a grounding issue. My plan is to:
1. Fire up heater and after it reaches temperature, raise the temperature to cause the heater to fire up again.
2. Remove the second ground
3. Raise the temperature and witness the failure
4. Attach the second ground
5. Raise the temperature and witness success.

This is what happened:
1. Fired up the heater.
2. When it reached temperature and shut off I raised the temperature to cause the heater to fire up again.

Heater did not fire....it failed!!! So I'm thinking, "Forget my stupid test".
I wait a while and fire up the heater (11th cold fire in a row).
The heater reached temperature and shuts off.
I was working on something else. When I checked the heater the "service heater" light was on. This tells me re-ignition failed.

So its been a while, I attempt a 12th consecutive "cold fire"....and guess what? Heater won't fire.
So I shut off the power to the heater for 10 seconds.
I attempt another "cold fire".....heater won't fire.
Three flashes on the ignition control module which indicates "ignition lock".
I checked the ohms across the igniter....read 52 ohms.

So I think we are getting "unpredictable results".
That's the phrase we used when I worked at IBM in the 80s when we had no idea what was going on.

So I guess the next stop is the ignition control module.
This is my last attempt before trying to find a competent tech.
My reasoning is as follows:
Cost of ignition control module on Amazon: $130
Cost of tech if it is the ignition control module:
$90 to come out
$100 labor
$230 for ignition control module (or some cost significantly more than Amazon)
So I figure that I'll gamble the $130 to avoid the $400

Couple of days to ship....I'll let you know how this turns out.

Any suggestions for a heater tech in the Harrisburg, York, Lancaster, Mechanicsburg area of south-central PA?

Question: What is the FC on the ignition control module? What does the fact that I get only .8vdc instead of 3.0vdc mean?

Thanks for your help.
 
I replaced the ignition control module and I'm still getting unpredictable results.

It did something, however, that I had never observed. After replacing the ignition control module, the heater fired up "cold". It shut-off at 80 degrees. I then increased the temp to 95 and it fired. So after it reached 95 degrees, I headed out to the spillover spa and wife joined me. She asked if the heater was OK. I said that I was waiting for it to fire at 95. Well, about that time the blower came on and I waited to hear the "whomp" of the heater starting. I did hear the "whomp"...but a minute later the water was still not heater entering the hot tub. I walked over to the heater and it was trying to light. So the heater ignited for a very short time then shut off for some reason. I never observed that before.

I checked the FC. It read 1.0vdc instead of .8vdc on the old ignition control module. Still nowhere near 3.0vdc. I'm checking the FC when the heater is running. Is this correct, or do I need to check prior/during heater ignition?

Anyway....

I have called a service tech. They will be out next week sometime. I'll let you know what he finds.
 
Still waiting for tech to show up. I heated the pool on Friday, Saturday, Sunday. Sunday was key because May 10th is Mother's Day and the wife's birthday!!! Each day the heater ran about 8 hours. Each day the heater started right up in the morning. When the temp was achieved it shut off. When the temp dropped a degree, the heater attempted to restart and failed. I did this for three days straight. Why won't this heater restart? I think the first igniter was weak. Perhaps the second igniter has a crack. I guess I could: (1) check the resistance of igniter, (2) run the heater to temp, (3) observe failure to restart, and (4) check the resistance of the igniter. If the a crack in the igniter is the problem I should observe very high resistance. Any other ideas that I can plant in the tech's brain?
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply