Aquastat for DHW Question

Ed_5

I have a Burnham DHW heater with a Honeywell L4006 Aquastat connected to a Tekmar 262. If I turn the temp. dial up and down a few times it starts to work for a few days then quits working again. The stat is 1 year old, should I replace or can this be repaired. If I replace is there something out there that would be a better choice? Thanks for any help. -Ed

hydronicsmike

262 tekmar Boiler Control and DHW

Ed, You could use a tekmar 071 Sensor in place of the Aquastat and wire it straight to terminals 19 (COM) and 20 (DHW) on your tekmar Control without having to apply power. With the 071, you will actually gain a couple of features, such as Boiler Temperature Reset based on DHW Load.

I hope this helps. Please feel free to contact tekmar directly at any time at 250-545-7749, or visit the web site at www.tekmarcontrols.com.

Mike

Ed_5

Mike, I like that suggestion. I'm wondering why it wasn't set up that way in the first place. Will I have to change any other wiring on the 262? Looks like I'll have to do some programming changes as well. I wonder if there are any Tekmar experts in the West suburbs of Chicago? -Ed

hydronicsmike

I am unsure....

....why they didn't do this to begin with. Normally a DHW Tank comes with an Aquastat and an extra 071 tekmar DHW Sensor doesn't. This must be why they used the Aquastat.

Not much wiring has to be changed. Mainly, disconnect any Aquastat wiring from the 262 and then wire the new DHW Sensor to the DHW Sensor and COM terminals as mentioned above. Then there will be a "DHW SENS" Setting in the 262 Control that is currently set to "NONE" and this one will have to be changed to "DHW". Then you will find a new setting labeled "DHW OCC" and that is now the Water Temperature you want to maintain in the Tank. Before, with an Aquastat, you used to have a "DHW XCHG" Setting in place and that was the water temperature that was delivered to your tank when ever there was a call. With the new Sensor, the Boiler Water Temperature will vary based on the load of the Tank and recovery time (Boiler Target Temperature is usually starting out at +40°F above the "DHW OCC" Setting).

I am sure there are plenty of excellent guys in your area that are familiar with tekmar Controls. This is not a big change as is. It would be best if you contacted the local Rep in that area, which is Bornquist Sales right in Chicago at 773-774-2800 and ask for Shawn Mansfield. He knows all of the local tekmar guys in your area.
I hope this helps. Please feel free to call tekmar at any time, should you have more questions or comments 250-545-7749.

Regards,

Mike

Ed_5

Mike, thanks again. I believe the 071 that came with the 262 was used for sensing the Boiler temp. I can get the 071 set up for my DHW but I'm wondering if the rest of the 262 was set up properly. I have 2 boilers with an outdoor sensor as well. I guess I'd like someone that's very familiar with the 262 to see if I'm set up for optimum efficiency. -Ed

hydronicsmike

Call me....

...and we'll go through the setup together. It's kind of difficult doing it on here. You'll be the Pro and I'll help you guide through it.

250-545-7749, ext. 214

hydronicsmike

Ed

I got your message. Thanks. Am glad you were looked after. Please never hesitate to call us back, should there be anything we can do for you.

Regards,

Mike