Can a delta T circulator be used to replac termovar valve?

[TimCroft]

I'm looking for a bit of advice. I have a Tarm Excel 2000 boiler with STSS 620 gal storage piped in a standard Tarm layout. I am thinking about eliminating the Termovar on the boiler loop and replacing the grundfos 15-58 with a Delta T circulator . I am tired of the termovar leaks. If the valve on the bypass loop is kept halfway closed as recommended by Tarm, do you think a Taco Delta T can maintain a stable boiler temperature?

Thanks.for your thoughts,

Tim

 

[SmokeEater]

Have two Taco delta T circs and they work very well. One, a 007, is on the boiler with the high temp sensor on the boiler output and the low temp sensor on the boiler return. I set the delta T at 30 degrees and have my aquastat start the pump at 160. My idea was to allow them to pump just the amount of btus needed without "burning" to much electricity. They do that well, because I have never seen either in the last month run at full speed. They have only run at full when starting, but they're programmed to do that by Taco. I still use the Danfoss on the return loop to the boiler, but I've never seen the return temp go below 160 when the boiler is on. The other Taco is a 0012 and it pumps to the all the heating circuits. The nice thing about it is that it only pumps the btus you need without wasting energy. I think with tweeking your aquastat and the delta T settings, you could easily replace the Termovar. I'd probably leave in the balance valve though.

 

[huffdawg]

On a house loop that has multiple loads pulling off it might be a good application for a t pump. I think there are a few others with t pumps for boiler protection. I think it called bang ,bang control. Also maybe on a storage loop? How much is the taco pump selling for now.

Huff

 

[SmokeEater]

Huff, the 007 variable speed pump I have on the boiler was just under $180 and the 0012 variable was $380. I use them basically to save noise and electricity.

 

[RobC]

In the "Stickies" look at primary / secondary. HR has a nice set up for the first layout that comes up. I think this is his "new and improved" version. Could something also be done using a buffer tank ?

 

[TimCroft]

Have two Taco delta T circs and they work very well. One, a 007, is on the boiler with the high temp sensor on the boiler output and the low temp sensor on the boiler return. I set the delta T at 30 degrees and have my aquastat start the pump at 160. My idea was to allow them to pump just the amount of btus needed without "burning" to much electricity. They do that well, because I have never seen either in the last month run at full speed. They have only run at full when starting, but they're programmed to do that by Taco. I still use the Danfoss on the return loop to the boiler, but I've never seen the return temp go below 160 when the boiler is on. The other Taco is a 0012 and it pumps to the all the heating circuits. The nice thing about it is that it only pumps the btus you need without wasting energy. I think with tweeking your aquastat and the delta T settings, you could easily replace the Termovar. I'd probably leave in the balance valve though.

thanks Smoke eater,
The Tarm runs up and down between 155 and 180 in the current setup. Plumbing the boiler my first experience six years ago and I would like to redo the whole set up. Have a grundfos 15-58 on the secondary loop and 2 15-58s on the house loops. I'm thinking about eliminating all these and using zone valves and one Alpha without the balancing valve and the second termovar which returns hot house loop water to the secondary loop.

Was just a bit worried that pushing all the house loop return water through the storage would leave a huge delta t on the return to the boiler. Your Taco runs very slowly when the delta is more than thirty right? you think it would make more sense to just fit a delta T circulator rather than a delta P on the house loops?