I’m stumped.

[Chestrockwell75]

Hello everyone, I'm new here but have been in the industry for 15 years and installed or repaired thousands of fireplaces. Recently encountered a issue that has me stumped and could use some help. So a friend picked up a lopi Berkshire ( 2005 pre greensmart ) on Craigslist for next to nothing. Previous homeowner couldn’t keep it running. Local Travis tech had been there multiple times. Anyhow he brings it over i tear the thing down , replace the pilot assemble ,check and clean burner orifice , check wiring and replace snapdisc , blow out all the old white carbon deposit I. It and the exhaust . Then repainted the inside to clean it up for him. I checked the emberglo burner tray for any cracks or separation it looked great. Thing was like a new stove when finished . On to installation it was a simple run 3 1/2 up and 90 out the wall. Used brand new Simpson duravent . Fire the thing up runs great , I adjusted the air intake to get the flames looking optimal , vent restrictor is in position one. After about 20 min the thing quits pilot and all. Relight immediately runs for another 3-4 min then turns off again , then a minute or less each time after that . Thermopile is at 560 standing 245-255 with burner on , pilot looks great , no ghosting or agitated look. But just to be sure I put a pilot shield around it after it cools. start it back up it runs for ten minutes then quits again , and less time every time after. Im thinking the valve may be on the way out ( Sit 820704 ) but I’ve never seen one act like this. Usually they just quit.
any thoughts or recommendations are appreciated thank you

 

[DAKSY]

Probably time for a new gas valve...I am not familiar with the Lopi units,
or what valve they use, tho. There are testing procedures to determine if the valve is good.
Without knowing WHAT valve it has, I don't know what testing procedure to look for.
Most can be tested for resistance, after all connections have been removed, but you'll
have to research to find the range of good readings...

 

[Chestrockwell75]

Probably time for a new gas valve...I am not familiar with the Lopi units,
or what valve they use, tho. There are testing procedures to determine if the valve is good.
Without knowing WHAT valve it has, I don't know what testing procedure to look for.
Most can be tested for resistance, after all connections have been removed, but you'll
have to research to find the range of good readings...

its a SIT 820 nova series 820704 . Travis and Mendota use them exclusively, looks like I’m gonna have to take it back apart to test the ohms reading , considering getting to the back of the valve is next to impossible in this stove. Thanks for your reply have you ever seen , a valve act in this manner. I’ve seen some that fail and won’t do anything , some that leak. Never work in the manner that it runs then shuts down completely. Then after less and less time running.

 

[DAKSY]

I recently replaces valves- BOTH SIT & BOTH in
15 year-old Regency U39 gas stoves.
BOTH also died gradually...

 

[Fingerlakes Fireplace]

Since your pilot is dropping out, as well as the main burner, the thermocouple or pilot solenoid is causing it to shut down. If it was the thermopile or burner solenoid, the pilot would remain lit. My first guess would be a venting issue.
Watching the pilot when it drops out, will be the first step in diagnosing a venting issue. If the flame is the same as when it's cold and not running. It is not a venting issue. If the pilot flame starts looking very bluish, almost transparent, then that is your problem.
It could also be a bad thermocouple.( when we install a new part, we always assume it to be good!)
Without using an interrupter block, and checking amp draw when it's hot, it will be hard to diagnose.
But on the flip side, if the previous owner couldn't keep it lit, and you replaced one of the two parts in this system,(thermocouple) that does point toward the gas valve.( I have that valve in stock on my service truck, and if you are within an hour of Phelps, you are in my service area)

 

[Chestrockwell75]

Since your pilot is dropping out, as well as the main burner, the thermocouple or pilot solenoid is causing it to shut down. If it was the thermopile or burner solenoid, the pilot would remain lit. My first guess would be a venting issue.
Watching the pilot when it drops out, will be the first step in diagnosing a venting issue. If the flame is the same as when it's cold and not running. It is not a venting issue. If the pilot flame starts looking very bluish, almost transparent, then that is your problem.
It could also be a bad thermocouple.( when we install a new part, we always assume it to be good!)
Without using an interrupter block, and checking amp draw when it's hot, it will be hard to diagnose.
But on the flip side, if the previous owner couldn't keep it lit, and you replaced one of the two parts in this system,(thermocouple) that does point toward the gas valve.( I have that valve in stock on my service truck, and if you are within an hour of Phelps, you are in my service area)

Thank you both , I will definitely be in touch if I need that valve . I have to go look at a job Saturday morning in Skaneateles. Soo I could meet you in Waterloo or something after. I’m gonna rip the thing apart again at some point this week to test the valve And thermocouple.One thing I did notice , after looking at the manuals from the models after Is they moved the pilot assembly from the rear left corner ( near one of the air intakes ) too the middle left and the burner drops around it. Also the newest versions Gs2 have an air deflector that attaches to the back of the burner tray , the box has remained the same they gust changed the position of the pilot and the burner. I did put a chincy little pilot shield on the left side of the pilot. I may try making something a little nicer to wrap around the pilot more. ill report back with my results.

 

[Fingerlakes Fireplace]

If the incoming intake air is causing the problem, it should be very easy to identify by watching the pilot flame.

 

[Chestrockwell75]

If the incoming intake air is causing the problem, it should be very easy to identify by watching the pilot flame.

Well you we’re on the right track. Soo I went over there and tested the thermocouple and valve both were good. Previous owner must if had the valve replaced because the date code on the back was 1726 ( July , 2017 ) for 2005 stove. I take the glass off and we have some drinks waiting to see if this thing shuts down . It runs great , immediately I said venting. Previous homeowner had 2’ then a 90 out the wall. Which my friend took as they were painted to match the stove . His configuration was up 3.5’ and out through a block basement wall. But the only we reused was that 2’ and 90 which my friend cleaned out with compressed air. After it cooled down a bit I took that section of pipe he brought apart ,and sure chit in the 90 there was a 1 1/2” gap where the inner pipe had separated on part of the swivel. You couldn’t see it looking through the pipe with the 2 foot section attached. Soo thank you both for your help with this issue. The thing I find funny about the whole situation now is , the previous homeowner was soo pissed off dealing with this thing racking up service calls and replacing parts. He basically gave it away , then put in a pellet stove while we have natural gas relative cheap.