LAARS MFTCW, MFTHW, FTCF, FTHF Won't achieve HIGH Temperature. Boiler won't go into high fire.

LAARS MFTCW, MFTHW, FTCF, FTHF Won't achieve HIGH Temperature. Boiler won't go into high fire.

An Outdoor Temperature Reset Supplied with the Boiler MUST MUST MUST be used.

The D.O.E (department of energy) regulations regarding outdoor temp. reset DOES affect this boiler in most all serial # date of manufacturer #'s !

It has been noted that all MFTHW . FTHF , FTCF and many MFTCW  models are affected .

 

As per the D.O.E , the maximum temperature achieved is 140 degrees F  (minus the differential of 8 degrees F)  without an outdoor sensor or some form of external modulation. ie tekmar (0-10) , (4-20).


* For troubleshooting and testing purposes, a 100K resistor wired to the O/S terminals of the boiler (in place of outdoor sensor) can be utilized.