Weil-McLain Ultra Gas Series 3 problem

refrigerationguy

Hello all,

First post to the board...looking for ideas. Ultra gas series 3.  Problem: Primary pump does not get power when there is a call for heat.  Boiler functions perfect for domestic indirect.  I replaced control board, and it does the same thing.  I changed the board on this about a year and a half ago because it would not energize the gas valve.  Anyone else have alot of problems with these boards?  I jimmy rigged the primary loop pump to come on with the heating loop pump so that they can have some heat and it works ok.  Just can't get that board to power up the primary pump.  I really dont think the new board could be bad as well.  Also I noticed there is a high and low voltage fuse in this board.  Low voltage fuse ok, but I was in my car and didnt have my meter to check the high voltage cartridge fuse.  If that fuse was blown wouldn't it prevent the domestic pump from coming on also? Ideas? Thanks in advance

Jean-David Beyer

I do not wish to insult you...

I have one of those, and it has been working since May 2009. I use all three thermostat inputs to the control board, and would use 4 circulator outputs if it had four.



Did you check the setup of the board with the buttons on the front panel and the installation manual?



Mine is set up so that if priority 1 is calling for heat, only the circulator to the indirect hot water heater runs. Circulator #1 is the only one that runs. The indirect is tied across the supply and return in the primary loop.



The boiler circulator is circulator 2. This circulator runs if either priority 2 or priority 3 (or both) call for heat. If priority 2 is in control, circulator 3 also runs to operate my downstairs zone. If priority 3 is in control, circulator 2 also runs, and since there is no circulator 4 output, I have a Honeywell RA832A relay box to run Circulator 4 which is for the upstairs zone.



THe #4 circulator may run even if the boiler circulator is not running (because the indirect is running). Harmless since the indirect does not run much. It may also run if the downstairs circulator 3 is running. That may help the upstairs a little because there is hot water going to both zones in that case; but not much because the downstairs gets cooler water than the upstairs does. Here too, there is no problem because the heat load upstairs is very low.



W-M say to run only one circulator on each circulator output, so I hope you are using a relay box to control the other one until you get this problem sorted out.



Did you happen to check both fuses in the board you replaced? If either fuse is bad, you could have problems.



You should check carefully that the control board is programmed correctly. If you use the usual setup, the indirect is connected to priority 1 thermostat input, and its circulator is connected to circulator 1 output, and the program should say to run only circulator 1 on priority 1.



The boiler circulator is usually #2, and the secondary circulator(s) are circulator 3 and others not discussed. I would program the boiler circulator to run if either priority 2 or priority three are requesting heat. And Circulator 3 should run if priority 2 is asking for heat. If you have another zone, it might go into priority 3, and you would need a separate relay box to run its circulator.



Good Luck.