Laars MFTHW Heat Only Cascade Instructions
Cascading FT (MFTHW) Heat only boilers
Tuesday, April 18, 2017
4:59 PM
Right now all we can do is cascade the control signal between boilers. We are not offering cascading venting as of now.
The MFTHW (heat only) boilers can be cascaded.
You will need the following parts:
FT1868 Supply Sensor - one per system (Can also use a tekmar 10K sensor).
FT1861 Cable - One per boiler (two boilers =2 cables, three boilers =3 cables, etc. ) !
Each cable comes with an end resistor ! Remove the end resistor from the cable that will be the "master" boiler cable . The molex connector of the "master" cable then plugs into the second "member" cable . You will have an unused connector of the cable on the "master" boiler cable.
The "member" cable will have the end resistor. In essence one of the end resistors will not be used , and should be saved for future use.
The temperature sensor should be attached to the system supply piping as close to the manifold as possible . In the case a hydro separator is used then the sensor should be placed on the SYSTEM supply side of the hydro separator ! Use the supplied ties that come with the sensor or longer wire ties if necessary.
WHEN COMPLETED SETTING PARAMETERS 28 AND THEN 27, THE MASTER BOILERS SCREEN SHOULD LOOK LIKE THIS ( NOTE THE LOWER LEFT OF THE SCREEN SHOWING 0 AND 1). THE BOLD LINE UNDER THE 0 MEANS THAT BOILER ADRESS 0 IS FIRING WHILE ADDRESS 1 IS NOT FIRING . THE BOLD LINE UNDER ADDRESS 0 IS PRESENT WHILE THERE IS NO BAR UNDER 1.
IF BOTH BOILERS WERE FIRING THEN A BAR WOULD BE UNDER BOTH ADDRESS 0 AND 1 .
THIS PHOTO (BOILER ADDRESS 1) SHOWS FOLLOWER BOILER ADDRESS 1, AND AS YOU SEE IT IS SHOWING US THAT BOILER ADDRESS 1 IS NOT PRESENTLY FIRING ! THERE IS NO BAR UNDER THE 1 .
AS A REMINDER… THE SEQUENCE IN WHICH PROGRAMMING OF CASCADING IS DONE IS VERY VERY IMPORTANT !
!!! PROGRAM PARAMETER 28:CP FIRST ! THEN AFTER THAT PROGRAM PARAMETER 27:CN !
ANY QUESTIONS ON THIS, CONTACT KENNY
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