Tekmar 256 wiring schematic
#1
10-22-10, 08:35 AM
Tekmar 256 wiring schematic
Getting ready to hook up Tekmar 256 control to existing boiler with standing pilot, L8148E aquastat and cast iron radiators with no zone control valves. Previous posts have covered this but I have the following questions:
- can existing t-stat wiring thru L8148E remain in place to start circulator on demand and just re-route burner control to 256?
- if this approach is acceptable, how is the burner control wiring configured to maintain the high limit safety feature on the aquatstat? A previous post suggested re-routing B1 from L8148E to Term 5 on 256 and from Term 6 back to B1 on aquastat if my understanding is correct.
Tekmar diagrams show the option of an additional relay for controlling the circulator, but none of their diagrams show how to wire in with existing aquastat.
A wiring schematic for this applicaton would be very helpful and greatly appreciated. Thanks.
- can existing t-stat wiring thru L8148E remain in place to start circulator on demand and just re-route burner control to 256?
- if this approach is acceptable, how is the burner control wiring configured to maintain the high limit safety feature on the aquatstat? A previous post suggested re-routing B1 from L8148E to Term 5 on 256 and from Term 6 back to B1 on aquastat if my understanding is correct.
Tekmar diagrams show the option of an additional relay for controlling the circulator, but none of their diagrams show how to wire in with existing aquastat.
A wiring schematic for this applicaton would be very helpful and greatly appreciated. Thanks.
#2
10-22-10, 03:58 PM
A previous post suggested re-routing B1 from L8148E to Term 5 on 256 and from Term 6 back to B1 on aquastat if my understanding is correct.
Tell us what make/model boiler you are wiring this to.
You are aware that you can NOT do a FULL outdoor reset on a conventional non-condensing boiler without some special piping to prevent flue gas condensation, correct?
On a gas fired boiler, you don't want to set the BOIL MIN below 155-160°F.
The relay contacts at terminals 5 & 6 on the 256 are rated at 240VAC and 5A, so it seems possible that you could use this to switch power to the burner... BUT...
In a case such as this, your best recourse would be to ASK TEKMAR. I would not trust strangers on the internet with this type of question. If Tekmar says it's OK, then it's OK. If Joe Schmoe or NJ Trooper says it's OK, then VERIFY before proceeding! No matter how good a BS'er someone is, you still have NO idea of their real qualifications.
