Castle Serenity Stove - Works Well For ~20 Min. Then Randomly Shuts Down. Please Help!

[PleaseHelpWithStove]

Hello, I have a Castle Serenity stove that I have been using for ~6 years now as the main source of heat for my home. Last year I had to replace the igniter, but that is the only thing I have replaced on it so far. We recently gave it its annual deep clean like we always do, gave it a new bag of pellets and it would ignite and achieve its usual flame for 15-20 minutes then suddenly it would shut down, saying to "check the hopper" and "check the burn pot". We've taken the pellets out, cleaned the auger completely, checked that it is moving before refilling it, no issues with the burn pot and again everything is very clean from just having done the annual deep cleaning. Tried it several more times and it does the same thing every time, seems to be working just fine then suddenly shuts off with the same notifications after heating for 15-20 minutes.

We are at a loss as to what the issue could be. We replaced the proof of fire sensor with the spare it came with and that did not fix it. Checked all the connections, brushed and vacuumed all the pipes again, took the motor and auger out and checked them, ran the diagnostics including the vacuum thinking that could be the issue but its saying everything is working fine.

I had e-mailed Castle customer support Oct 7th explaining my issue, and only just received a reply an hour ago and it was very unhelpful - didn't help to troubleshoot my issue at all, just gave me the cost for a "retrofit" and that was it. I just had to e-mail them back asking if that would 100% fix my issue and if it does not if I would receive a full refund for the item, I'm worried I'll have to wait another week for a response and we really need this up and running ASAP. Everything I've read about the stove working fine then suddenly shutting off goes off into replacing the motor, the control panel, the proof of fire sensor - can anyone please help me figure out what the exact issue is? I unfortunately do not have the income to be spending all this money on parts that may or may not fix the issue, or a new stove, so any advice is appreciated. Thank you!

 

[Whitenuckler]

Hello, I have a Castle Serenity stove that I have been using for ~6 years now as the main source of heat for my home. Last year I had to replace the igniter, but that is the only thing I have replaced on it so far. We recently gave it its annual deep clean like we always do, gave it a new bag of pellets and it would ignite and achieve its usual flame for 15-20 minutes then suddenly it would shut down, saying to "check the hopper" and "check the burn pot". We've taken the pellets out, cleaned the auger completely, checked that it is moving before refilling it, no issues with the burn pot and again everything is very clean from just having done the annual deep cleaning. Tried it several more times and it does the same thing every time, seems to be working just fine then suddenly shuts off with the same notifications after heating for 15-20 minutes.

We are at a loss as to what the issue could be. We replaced the proof of fire sensor with the spare it came with and that did not fix it. Checked all the connections, brushed and vacuumed all the pipes again, took the motor and auger out and checked them, ran the diagnostics including the vacuum thinking that could be the issue but its saying everything is working fine.

I had e-mailed Castle customer support Oct 7th explaining my issue, and only just received a reply an hour ago and it was very unhelpful - didn't help to troubleshoot my issue at all, just gave me the cost for a "retrofit" and that was it. I just had to e-mail them back asking if that would 100% fix my issue and if it does not if I would receive a full refund for the item, I'm worried I'll have to wait another week for a response and we really need this up and running ASAP. Everything I've read about the stove working fine then suddenly shutting off goes off into replacing the motor, the control panel, the proof of fire sensor - can anyone please help me figure out what the exact issue is? I unfortunately do not have the income to be spending all this money on parts that may or may not fix the issue, or a new stove, so any advice is appreciated. Thank you!

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Maybe the Proof of Fire switch

 

[PleaseHelpWithStove]

The stove comes with a built in 2nd POF sensor where you just swap the plugs over from the original to the spare and start it up like normal according to Castle's YT video. We had swapped it over when it was first giving us this issue and it didn't change anything unfortunately. I wonder if both of the POF sensors are shot or the blue plugs that go with it are fried? I don't see anything visually wrong with them but I'm not sure how to check if they are "good" or not.

 

[NS P-68]

Check your wiring diagram in your manual and see if your stove has a low limit switch. If it does, the stove has to reach a certain temperature within a set time to go into run mode. If so , you can bypass this by joining the 2 wires together and see if it continues to run past the 15 - 20 minute mark. If it does you'll need to replace this limit switch. It's possible this switch is in a location where it's covered in ash and just needs to be cleaned.

 

[PleaseHelpWithStove]

Might've found the issue I think 😂 the POF sensors are COMPLETELY rusted out on the side that connects to the stove! So that is clearly something that needs to be remedied ASAP and hopefully that fixes it.

 

[johneh]

Give that switch a good cleaning, and sand the surface clean. Try it again.
Rust and ash are fantastic insulators

 

[Whitenuckler]

The stove comes with a built in 2nd POF sensor where you just swap the plugs over from the original to the spare and start it up like normal according to Castle's YT video. We had swapped it over when it was first giving us this issue and it didn't change anything unfortunately. I wonder if both of the POF sensors are shot or the blue plugs that go with it are fried? I don't see anything visually wrong with them but I'm not sure how to check if they are "good" or not.

POF switches would be normally open, and close on a certain temp. You would need an ohmmeter ($20 multimeter) and then disconnect it, and test with heat.

 

[PleaseHelpWithStove]

We installed 2 brand new POF sensors in it today and it is still doing the exact same thing it did before 🥲 They are registering it at 80C in the diagnostic menu, which is also what it was doing with the old rusty sensors. So now I don't think that is what the issue was unfortunately... Seems like it will work well for 20 minutes then the rate of pellets dropping down slows, and then the fire peters out. Currently trying to see if I increase the rate of pellets dropping if that will make a difference.

 

[Whitenuckler]

We installed 2 brand new POF sensors in it today and it is still doing the exact same thing it did before 🥲 They are registering it at 80C in the diagnostic menu, which is also what it was doing with the old rusty sensors. So now I don't think that is what the issue was unfortunately... Seems like it will work well for 20 minutes then the rate of pellets dropping down slows, and then the fire peters out. Currently trying to see if I increase the rate of pellets dropping if that will make a difference.

You could be looking at a control card issue or some sort of bad connection. I'd shut the power off and check all the connections you can get at.

 

[NS P-68]

Shows a thermocouple in the wiring diagram so maybe something to check next...?

 

[Whitenuckler]

Shows a thermocouple in the wiring diagram so maybe something to check next...?

I did search and AI generated this: According to this you are right the POF might be from the probe

Key Components in the Wiring Diagram

• Power Supply: 120V AC input with line (RD) and neutral (WH) wires protected by 6A fuses. [1]
• Controller Board: Connects to internal components via a 4-wire serial cable (#4, #3, #2, #1 pins) and a 16-pin interface module. [1, 2]
• Igniter: 120V igniter element with a replacement kit part number 720307. [1, 2]
• Motors & Blowers:
  • Auger Motor (M 1~): Feeds pellets into the burn pot.
  • Exhaust Blower (M 1~): Pulls air through the firebox and vents smoke.
  • Room Blower (M 1~): Circulates heated air into the room. [1]
• Safety & Sensor Switches:
  • Thermodisc (52°C / Overtemp Switch): Prevents overheating (part #34004, 120VAC, 15A, 200°F).
  • Proof of Fire (Thermocouple 30°C): Detects active flame.
  • Room Temp Sensor: Monitors ambient room temperature.
  • Vacuum / Pressure Switch (Micro-switch P): Ensures proper draft and negative pressure in the exhaust system. [1, 2, 3]