Tekmar 356

Jay_17

I am contemplating adding outdoor reset to my HW baseboard (gas). It is a simple loop system, no zones (yet), no DHW or anything. It looks like the Tekmar 256 is appropriate, any comments on the unit or other options?

Jay

Rick Kelly_3

controls

You might want to look into using a Taco 3-way iSeries mixing valve. It can be used with one less pump and it's actually made for Taco by Tekmar.

hydronicsmike

Jay, 2 options I would recommend....

If you want to do mixing for full Outdoor Reset, I suggest you use a 361 if you want to do Variable Speed Injection or a 360 if you want to use a Mixing Valve. I would go 361 over 356 because it can handle the boiler and system pump and therefore gain you Purging, WWSD and Exercising for those Pumps. With a 356 you always need a Relay for those pumps which by the time the Relay is bought and wired in, it most likely costs you the same. But you would not be able to take advantage of the added features the 361 would provide you with.

If you want a Boiler Control and only do Boiler Reset to a Boiler minimum, I would still recommend a 260, even though you don't have DHW. It has the extra System pump contact to gain you the same features (Purging, WWSD, Exercising) where the 256 doesn't.

In my opinion, it often is forgotten that an extra relay and extra wiring also costs money when a control is picked. For yourself, maybe have it priced out both ways and include the time it takes you to do the extra wiring. I would be surprised if there was a big difference between a 356 - 361 OR 256 - 260 by the time all is set and done. And then don't forget about the added features and benefits your customer will get as well.

Hope this helps.

regards,

Mike

Jay_17

Whoops

I typed 356 when I meant 256, sorry, no mixing here.
Thanks for the replys, The 256 does have WWSD but not the exercising feature, good point.
Jay

hydronicsmike

Yes, the 256...

...Shuts down the Boiler in WWSD but does not operate a Pump and therefore can't give the added features.

Mike

Jay_17

I see your point

I think you are right, between external relays and the other features of the 260 (which also has the indoor temp option, which seems useful) it seems like the 260 is preferable, even though I will almost certainly never do DHW.
Thanks
Jay

hydronicsmike

Thanks jay

Feel free to call me at any time, should I be able to help you with anything. 250-545-7749, Ext. 214

Regards

Mike