Laars Endurance

Yes...I will be going back and will post the start and shutdown numbers. The gas valve has 2 tiny screws on the face marked in and out. Certainly not the same size that are on my WM. I have an email in to TL and asked whether those are indeed the test ports.

Thanks a million...

T

Timco

If those screws are in a little cone you undo screw half turn to a turn and slip the manometer tubing over the cone

Screws are not in a cone, but apparently the top one is for incomming press(4-13 wc) and the bottom is the inlet offset press port (-.01 to -.10 wc)...The big torx cover is to the adjustment key

Apparently, I may be suffering from cross contamination of the combustion air as it is a direct vented unit in a double wall sleeve (in & out). Would I extend the exhaust tip to cure cross contamination?

T

So once my inlet pressure is verified in specs, I will adjust (lower) the gas while testing and watch the CO & stack temp drop since there is apparently no manifold pressure test port...Yes, it is a stainless inner, sealed combustion.

Thanks again!!

Tim

Endurance

Do the numbers change as it modulates ?

You MIGHT have a little cross-contamination, the inner pipe is sealed with silcone and tape. Much C-C will shut unit down.

I believe flame impingement is a probable cause of high CO here as the fire is blown through the HX coil to some degree. Maybe the coil just needs a light brushing.

It would be interesting to see what Laars has to say.

If I remember correctly, all tests and adjustments are supposed to be mede with the unit at high-fire. This is done by placing a jumper across two terminals.

Here is an exerpt from the manual

Check for cross contamination before attempting to adjust offset pressure. CO2 sampling may be taken at the exhaust terminal or at the sample port on the 3" exhaust located inside the unit. The CO2 values of (Nat. Gas CO2 of 9.0-9.6% with an offset of -0.01 to -0.10) (L.P. CO2 of 9.7-10.0% with an offset of -0.01 to -0.10) should be achieved when the unit is at high-fire. To manually fix the unit in high-fire, locate the four-pin connector on the bottom left of the control board and jumper the middle two terminals together. Note that during the prepurge cycle the gauge will indicate several in. w.c. negative pressure. Adjust the CO2 and/or offset pressure to the values listed above. When adjusting the offset pressure, the CO2 will reduce as the offset pressure is adjusted more negative. FINAL ADJUSTMENT OF THE OFFSET PRESSURE MUST ALWAYS RESULT IN A NEGATIVE PRESSURE UPON COMPLETION.