Where to set ball valve for Tarm

[Thom Griffin]

I've asked this before a year ago or so. I've got a Tarm with storage. The instructions called for a ball valve before the termovar valve that controls the loop back to the boiler or to the storage tank. The instructions said to set the valve to half way open and adjust as needed. However, it's never stated anywhere what the object is for the adjustment. Unfortunately, I didn't install all those nice temp probes on either side of the thermovar, so I don't really know what I'm aiming for.

Everything has always seemed to run fine, but it's hard to know if it could be improved. I have a drafty old farmhouse, and possibly inadequate radiation, though I don't think that's the issue.

One of the answers a few years ago was to just leave the valve cracked open a bit. It didn't seem to have any effect on anything.

 

[webie]

As temp probes just go get ur self a couple of cooking meat temperature thermometers , alittle duck tape and insulation over gives you a pretty good idea of your water temps .

 

[jebatty]

I have 1-1/4" gate valve instead of a ball valve, reason being is that the valve I had and didn't want to buy another valve. The gate valve has been in place since 2007. I also have a temp sensor on the pipe to the boiler after the Termovar, and the sensor feeds a digital panel meter temperature gauge which gives the temperature readout. The Tarm feeds only storage, and then the system draws from storage. If return from storage is about 135F or less, I have the gate valve opened 2 full turns from closed. If above 135F, one full turn. This results in return water at about 145-150+F to the Tarm. When storage return is above 170F, I may, but don't have to, shut the valve completely and open a bypass valve. I only do this if I want to charge the tank to about 190F top to bottom.

All of this said, there are many times I just leave the valve at 1-2 turns open and forget about doing anything else.

 

[Fred61]

Once you realize the function of the bypass you can make your own determination as to the amount of flow you might need.

The bypass tube sends a sample of the boiler water through the loop when the pump launches. If the temperature of the water is equal to or exceeds the value set on the protection valve, it will start to let water in from the system. when the system water goes below the value set the valve the Termovar will shut off the flow. It's basically the only way to get a sample of the boiler temperature to that location.

The reason they want a restriction in the bypass that is variable is that it is the route of least resistance in the loop and could reduce the circulation of water from the system. Restricting the flow down to no more than what is needed to sample the boiler temperature is the goal.

 

[Thom Griffin]

Once you realize the function of the bypass you can make your own determination as to the amount of flow you might need.

The bypass tube sends a sample of the boiler water through the loop when the pump launches. If the temperature of the water is equal to or exceeds the value set on the protection valve, it will start to let water in from the system. when the system water goes below the value set the valve the Termovar will shut off the flow. It's basically the only way to get a sample of the boiler temperature to that location.

The reason they want a restriction in the bypass that is variable is that it is the route of least resistance in the loop and could reduce the circulation of water from the system. Restricting the flow down to no more than what is needed to sample the boiler temperature is the goal.

Thanks Fred. That's a better answer than I've ever gotten from the otherwise great folks up in NH. I knew the function of the Termovar; that's well-explained in the literature with the boiler, but nowhere does it (or did it) explain what you did regarding the ball valve before the Termovar.