Sparks Modern Fireplace shuts down and comes back on?
Need a fresh set of eyes on a issue with a clients unit. I am a Custom Home Builder in AZ, never had an issue I cant solve and this one is baffling the manufacturer, installer, and my techs.
Unit: Sparks Modern Fireplaces / 19E / 6 foot lineal burner direct vent
Install: Great room, about a 12 foot vertical run with Duravent pipe, high wind Duravent cap, natural gas
* Unit starts and runs for 15-20 minutes, then shuts down, and re-ignites.
* Shut down cycle takes about 45-90 seconds. Burner goes out, then pilot goes out, pilot reignites, burner reignites.
* Pilot and flame look good, no ghosting of flame, no blue, no to bright yellow.
* Gas line checked and holding about 10-10.5 WC, even when other unit on same line is shutting on/off.
* Adjuster flu/intake dampers in all positions
* Changed out termination cap to many others, still issues
* Termination cap is 5' away from vertical wall and 24" above roof
* Manufacturer has provided all new guts (brain, pilot assemblies), replaced and unit still has issues. Basically aside from burner, entire insides are replaced. Only Flu pipe, cap, and fireplace metal box are existing original.
* Another brain installed, still issues.
* Rebooted remote, still issues
Any ideas on what we could try? I may cut out drywall on back side wall to inspect Duravent pipe connections. We have been baffled by this issue for many months. There is another Sparks unit, on same gas line, smaller unit, that works fine.
Much appreciate a fresh set of eyes on this. Thanks all
First of all, this is NOT a DIY forum so we are very limited as to what help we can provide. See Site Rules.
Second, thanks for providing a lot of information! Much more than we usually get.
Inspecting the venting at this point may be a good idea. However, you would need to disconnect the venting from the unit to ensure the installer removed any insulation or other packing from the appliance collar--been there/ done that. Be sure all joints are intact. You may need to seal them with Mil-Pac hi-temp. refractory cement (made for direct vent pipe).
Ensure no sources of negative pressure that could affect the venting, especially if it approaches around 25 Pascals negative.
That static gas pressure is actually a little high. Check with the mfr. on the maximum inlet pressure to that valve. Good you checked for inlet pressure under full load.
I didn't see where you ran the unit in continuous pilot to 'prime' the flue first. I would try this. Also, try running the unit with the glass temporarily off, just to ensure the gas controls are working properly. Stray air currents could still disrupt the air flows around the IPI pilot but this might rule out the gas train as the problem. Just because you have gas pressure does not translate into sufficient gas flow. Try it with the flame height turned down to the min. allowed (manifold pressure).
Other than these measures, you would need a pro in there. Where is this installed? We might be able to recommend someone. A six foot long fireplace is a challenge to get the air and products of combustion to flow properly through this long low box to the venting. Good luck!
Keep the fire inside the fireplace.