anyone running an HBX controller for radiant floor or boiler

im running a hbx model cpu-500 to controll my radiant floor, everything works great except it will not maintain min. temp. im curious to see if im programming something wrong? set up is very straight forward have min floor temp set at 90* but controller allows it to go below. not in warm weather shutdown mode either. help please!!

Shall we assume you are using this for CPU-0500 Mixing Application?

Set for Injection Pump?
If so, which drwg.?
Maybe this one??? >>>> #9. Mixing with On/Off or Modulating Boiler for use when a single boiler (either modulating or On/Off) is used
with a floating action valve (power open / power close).

Using for Outdoor Reset too?

Need more info, please.

set for pump injection, using singleon off boiler no outdoor reset

331camaro wrote:set for pump injection, using singleon off boiler no outdoor reset

McGiever wrote:
Which drwg.?

#9. Mixing with On/Off or Modulating Boiler for use when a single boiler (either modulating or On/Off) is used
with a floating action valve (power open / power close).

Do you have the above in Red type valve?

We're getting closer.

No power valves set up more like drawing 7 sorry for the confusion and thanks for the help. double checked wiring for mistakes, wired exactly to drawing 7. so now my question is will that configuration allow for a low temp min?

Let's start w/ this...

Are these set as below?


Heat Demand = On

Boiler Pump Selection = Off (This one puzzles me, maybe should be on.)

i tried it with the heat demand on, then it bypasses t-stat and maintains the max temp set on the low side all the time. boiler pump is off ill try on, and see what it does

also another part of the puzzle i dont have a slab stat, im only using a hbx100 t-stat to control using rm temp. should i drill a hole in the floor and put in a slab stat, i have a spare thermistor

Slab stat...could only make it better.
Probably, location of this stat would be critical.

What setting is Minimum Boiler Temperature?

160 with thermistor placed on first piece of pipe coming off boiler controller is not in boiler protection mode tried boiler pump on and it turns on the boiler pump and does not call for heat

What device do you have wired to controller at >>>> DS1?

ds1 is the thermostat. should i put my spare thermistor there and have 2 thermistors on the low side? or put spare thermistor on ds 2 i think im onto it now thank you!@!!!!!!!!

i think i need a strap on aquastat, spare thermistor idea didnt work looking for open or closed in mixing mode. do you think i should worry about maintaining a min temp in the floor or just let the thermostat turn it on and off? i was thinking to gradually start pumping warmer water thru the floor so when the cooler months come there isnt the initial shock of trying to heat a cool slab. just a thought probably over thinking it. slab stat might remedy this too. where would you suggest placing the thermistor? i was thinking in there permitor a few ft away from the manifolds since it would probably get a false reading if it were too close to the manifolds.

If you use a minimum temp for your slab, it will be to hot when the warm days occur.(Did that) WIthout an outdoor reset this will happen anyway.(Did that) And will still happen with an outdoor reset if the temp is cold and suddenly rises.(Yup) That is the drawback to a radiant slab. I just tried to even out the highs and lows with my tekmar injection system/with outdoor reset and it worked very well. I have no knowledge of the system you are using, but I am sure it will do the same thing for you that mine did. I did not use the slab monitor as I wasnt concerned about the temp of it, just wanted the temp to be close to setpoint, up or down. And the tekmar would shut down at a preset and adjustable high temp for the feed water to the slab. Keep playing with it, you'll love it when the bugs are worked out. Sound like McGiever has the knowledge to help.

Kevin

1, 2: Demand Signal 1
Apply heat demand from a dry contact.

2, 3: Demand Signal 2
Used for DHW or Setpoint demand. Dry contacts only.

4, 5: Modulating / Boiler Contacts / Heat Pump 1
Modulating, Boiler 1, and Heat Pump 1 Output. Also
used in differential setpoint output for modulating
devices.

Sensor Inputs

6, 9: Primarily used for boiler temperature but also
used for setpoint 1 temperature in Setpoint controls or
hot tank temps.

7, 9: Used for DHW or setpoint on Boiler controls and
low temperature system temperature on Mixing
control. Also used for setpoint 2 temperature or cold
tank temps.


What is connected to terminals 7 and 9?