Page 1 of 1

Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 2:38 pm
by Kungur
I have my radiant floor set up with a KA-2. I have a Primary loop and 3 zones off the Primary controlled by sepeate circulators. I have Tekmar 3 way valve to be able to supply the zones with apprx. 130F water temp.
Recently I noticed that while a zone is calling for heat and that circulator is running the supply temp if good. Then while being down by the boiler last eek I notice that while the zone circulator was running the Primary circulator came on and the water temp climbed about 15 degrees. The it fell back as soon as the Primary shut off.
The house is comfy and this is season #2.
I checked how the Primary is wired and it is as instructed.
So what's up?
Also,I probably should know, what is the criteriea for the Primary to turn on?
Thanks!!

Re: Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 3:07 pm
by Rob R.
What is controlling the primary circulator? If it is the triple aquastat, the circulator won't run if the low limit is reached. Perhaps one of your radiant zones dropped the boiler temperature enough that the aquastat shutoff the circulator until the boiler recovered.

Re: Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 3:33 pm
by Kungur
Yes, the Primary is controlled by the Triple Aquastat.

Re: Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 3:42 pm
by Rob R.
What settings are you using on that aquastat? Do you use the tankless coil?

Re: Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 5:00 pm
by Kungur
Just saw your post. I will check later as I am on my way out.
Yes, I do use the coil.

Re: Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 9:18 pm
by Kungur
Rob,
Here are my settings on the Triple Aquastat
150F Lo
160F Hi
15 degree Diff

Re: Primary Boiler Circulator Question

Posted: Sat. Feb. 25, 2012 9:34 pm
by Rob R.
You should keep at least a 20 degree spread between the high and low limit settings. Try 150/180/10 and see how it runs.

Re: Primary Boiler Circulator Question

Posted: Sun. Feb. 26, 2012 7:55 am
by Kungur
Thanks Rob.
I will give it a try. I cannot remember how or why I came up with those settings.

Re: Primary Boiler Circulator Question

Posted: Sun. Mar. 11, 2012 6:50 am
by oliver power
Rob R. wrote:What is controlling the primary circulator? If it is the triple aquastat, the circulator won't run if the low limit is reached. Perhaps one of your radiant zones dropped the boiler temperature enough that the aquastat shutoff the circulator until the boiler recovered.
Yes Rob R., My Kaa-2 works as you describe.