Tarm Solo wiring

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New Member
Dec 30, 2022
Shokan, NY
HI ,
Recently I purchased a Tarm Solo 30 which needed some fire box repair. I got that taken care of and installed the unit in a back room of my garage. It is plumbed into my Weil McClain oil boiler with an additional circulator to force the water in a loop through the wood boiler then through the oil boiler. I have trouble maintaining good boiler temp in the Tarm. It seems to me that the circulator should not run until the Tarm us up to temp. When I power up the Tarm it kicks the circulator on immediately. Any thoughts?
Thanks Rob
It is difficult to reply without having a piping and electrical schematic of your set up. Electrically, you should be controlling the circulator via a temperature switch that will cycle the circulator On and Off. The circulator should not come on immediately when you power up the Tarm ,unless the temperature is such that the temp switch is requesting the On state for the circulator.

I have a Tarm Solo 55 that I am going on my 43rd year with. Basically, my Tarm supplies all the heat to my house by circulating water through a 2 row hot water coil that is installed above my heat pump air handler. My initial lesson was when I fired up my Tarm for the first time. When I had the boiler up to temperature (180 degrees), I started the circulator. After about 15 minutes, my boiler temperature dropped 20 degrees to 160 degrees. I thought my brand new boiler was defective. I had my balancing cocks and trim valves wide open. The water through the hot water coil was at a very high flow rate. Once I figured out the hot water coil was removing more heat from the boiler than the fire could supply, I reduced the water flow with the balancing cock and trim valve that I installed. After that all was good. I am using that configuration today and it works great. The simplicity of my set up with the maintenance/trouble free operation of my Tarm is outstanding.

John M.
My system has storage and when the water in storage drops below 110F an aqua-state automatically starts the oil boiler. Until that point the oil boiler just sits there cold till it's provided power to fire up.
Once a fire is started and the temp of the water that is getting sent to storage climbs above the set temp the oil boiler is cut from power and will sit cold until it is required.
What did you install for boiler temperature protection? You should have something that maintains the return temperature of the water returning to the boiler.
I have Tarm 40 and have a aquastat that controls the circulators. On mine I have it set to come on at 140 but you could set it at whatever you want. The only thing the Tarm controls is the fan.
Go to woodboilers.com

That’s the Tarm dealer. They have piping diagrams and wiring schematics for your boiler online.

It may take a few mins of looking but they should have what you need to help you with your layout.

The older I get the more I appreciate manuals and diagrams from the manufacturer
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