Tarm circulator on supply instead of return

penfrydd said:

Tarms drawings all show C-3 circ on return line. All the boiler guys I speak to tell me that's old school. Most circs are now on the supply side. As far as I can see, the supply should come out, then feed, then spirovent with expansion tank, followed by circ.

Any experience or opinions would be appreciated. Project is moving slowly, but steadily.

penfrydd

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I followed the Danfoss schematic which was "old school". Since I got a couple spots that have very small leaks when boiler is cold on my near boiler piping, I plan to do a little redo work next Monday to move my circ to suppy side and fix the leaks. I should have read the forum more closely and I would have done it right the first time.

C3 that feeds the Tarm is in that location because water needs to be pulled through the Termovar mixing valve. The mixing valve changes the placement of expansion tank and air scoop too, these are usually placed just before circulator.

Just a quick thought, are you taking into consideration your return temprature protection?

Huskers I was thinking about you leaks and reread your post.
Your leaks, Rector-Seal - True Blue works nicely. Wet the threads, tape and wet the threads again, I will also put a very light coat on the female side too. Some tapes have more thickness than others. Get appropriate tape for the pipe size.
Your circulator, The placement of the pump in relation to the Tremovar or Danfos valve is critical. Those valves only work as the diagrams show. On the return water side, first water passes through the valve - and then the circulator - and then the boiler. Then on the supply side you place the Spirovent and expansion tank.
No none of the locations are what your taught in "new school" plumbing but because of the location of boiler circulator and protection valve the next best place for the air elimation and expansion tank are after the boiler.
It is great that Tradsmen and Parts guys want to give advice I have learned much that way. But they don't normally use boiler protection valves.

RobC said:

C3 that feeds the Tarm is in that location because water needs to be pulled through the Termovar mixing valve. The mixing valve changes the placement of expansion tank and air scoop too, these are usually placed just before circulator.

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Yup.

RobC said:

C3 that feeds the Tarm is in that location because water needs to be pulled through the Termovar mixing valve. The mixing valve changes the placement of expansion tank and air scoop too, these are usually placed just before circulator.

Click to expand...

Or, for all the difference it makes, the boiler circulator can be on the boiler outlet as long as the tee that supplies the hot side of mixer is after the circulator. According to orthodoxy the air removal device and expansion tank tie-in go behind the pump.

--ewd

Here's an old post where I asked the same question.
https://www.hearth.com/econtent/index.php/forums/viewthread/40804/