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  1. #11
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by canuk View Post
    I'm womdering if the unit isn't the model 256.

    Anyway .....

    I'm not an expert on boilers .... however .... the way I see it the controller doesn't block the thermostat calling for heat.

    When the thermostat calls for heat this engages the circulating pump .... the Tekmar controller still allows this to happen but determines when to fire the boiler and for how long to maintain the temperature of the water.
    I wasn't considering the circulating portion of the circuit when I replied.

    However, my boiler has no mechanical circulation. I have a gravity feed system with one zone. The thermostat calls for heat and the boiler fires until the thermostat is satisfied. Blocking the operation of the thermostat (when the water temperature is warm enough and it's warmer outside) is the only way I could use such a device.

    On warmer days (40s & 50s), my boiler fires for a long time since it take a long to heat up and circulate that much water. By the time the radiators get hot and the thermostat is satisfied, the boiler stops but the radiators are still getting hotter. The system overshoots the thermostat by a large margin. Such a device by tekmar would prevent this but shutting down the boiler sooner on these warmer days when the boiler water reaches the lower temperature... thus giving the water more time to circulate and warm the large radiators.

  2. #12
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by canuk View Post
    I'm womdering if the unit isn't the model 256.
    I agree, I think you found the right one. It also includes both sensors; #70 & #71 as I spec'd out previously.

    http://www.tekmarcontrols.com/prod/256.shtml


    Look at this data sheet:

    http://www.tekmarcontrols.com/litera...robat/d256.pdf

    What they call the "Boiler Demand signal" input qualifies as a thermostat calling for heat.
    Last edited by sparky672; 11-18-2008 at 11:31 AM.

  3. #13
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by msligmr View Post
    I called my oil company and they said that a weather responsive control runs more than $1000. Is this truly the ballpark for the equipment? I don't want to mess with installing it myself; does anyone know where else I might look for weather responsive control installation?
    The unit on the TOH episode appears to be the Tekmar model #256

    Was that $1000 installed? Did they quote you just for the parts?

    Was that for this particular Tekmar model or something else?

    Perhaps call Tekmar and ask them for the name of your local sales rep. Then he can give you a name of local contractors.

  4. #14
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by sparky672 View Post
    I wasn't considering the circulating portion of the circuit when I replied.

    However, my boiler has no mechanical circulation. I have a gravity feed system with one zone. The thermostat calls for heat and the boiler fires until the thermostat is satisfied. Blocking the operation of the thermostat (when the water temperature is warm enough and it's warmer outside) is the only way I could use such a device.

    On warmer days (40s & 50s), my boiler fires for a long time since it take a long to heat up and circulate that much water. By the time the radiators get hot and the thermostat is satisfied, the boiler stops but the radiators are still getting hotter. The system overshoots the thermostat by a large margin. Such a device by tekmar would prevent this but shutting down the boiler sooner on these warmer days when the boiler water reaches the lower temperature... thus giving the water more time to circulate and warm the large radiators.
    i don't recall the subject program dealing with single zone gravity feed, thought DHW was also involved.

    your safety limit on boiler should control firing.

    if you don't have DHW off your boiler not sure this would work, but MAYBE Rich was using tekmar boiler reset module number 420, that includes the outside temperature sensor and the sensor inside. maybe the mixing station 704 would work for your system to correct the problems you're having.
    Last edited by Blue RidgeParkway; 11-18-2008 at 12:19 PM.

  5. #15
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by Blue RidgeParkway View Post
    i don't recall the subject program dealing with single zone gravity feed, thought DHW was also involved.
    I do not believe that should matter in this case.

    Quote Originally Posted by Blue RidgeParkway View Post
    your safety limit on boiler should control firing.
    It does. My point was that only one device is calling for heat and that's my thermostat.

    Quote Originally Posted by Blue RidgeParkway View Post
    if you don't have DHW off your boiler not sure this would work, but MAYBE Rich was using tekmar boiler reset module number 420, that includes the outside temperature sensor and the sensor inside.
    The 420 does not look like the small white devices Rich installed and demonstrated. The other poster found what I think is the correct Tekmar unit (#256) and it also comes with both sensors. The data sheet for the 256 also has a very basic diagram which describes the input for a "Boiler Demand Signal" which would be a thermostat.

    Data Sheet- Model 256
    Last edited by sparky672; 11-18-2008 at 12:13 PM.

  6. #16
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    Default Re: Weather Response Heating Control System

    i'll leave it to the boiler control experts but you'd need a boiler loop and a mixing valve to keep the boiler limit settings in spec for the boiler and prevent condensation and thermal shock you can't just run a regular boiler at lower than spec high and low limits.

    check out the mixing station I mentioned http://www.tekmarcontrols.com/litera...robat/d704.pdf

    anyway all the tek control panels have similar white covers. somewhere you'd need return pipe temperature sensors to safeguard the boiler from return temp shock. blessed on this end with zoned manifold system and system sensors that adjust for room temperature and distribution temperature fluctuations.

  7. #17
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by Blue RidgeParkway View Post
    i'll leave it to the boiler control experts but you'd need a boiler loop and a mixing valve to keep the boiler limit settings in spec for the boiler and prevent condensation and thermal shock you can't just run a regular boiler at lower than spec high and low limits.

    check out the mixing station I mentioned http://www.tekmarcontrols.com/litera...robat/d704.pdf

    anyway all the tek control panels have similar white covers. somewhere you'd need return pipe temperature sensors to safeguard the boiler from return temp shock. blessed on this end with zoned manifold system and system sensors that adjust for room temperature and distribution temperature fluctuations.
    I'm just an electrical engineer and not really a boiler expert but the system Rich installed in episode #707 was very simple and only prevented the boiler from firing if it was too warm outside and boiler water was over a certain set-point. He wasn't running it at all... just preventing the call for heat.

    In my situation, my boiler fires when the thermostat calls for heat and shuts off when the thermostat is not calling for heat. I have no pumps... water is always circulating by itself... warmer towards cooler... there is never any thermal shock since the water slowly heats, slowly circulates, and slowly cools. Interrupting the regular call for heat will not change that any more that messing with the thermostat more often.
    Last edited by sparky672; 11-25-2008 at 01:12 AM.

  8. #18
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    Default Re: Weather Response Heating Control System

    i'd have to watch the show again. in the meantime if you're grossly overshooting room temp at your thermostat couldn't you adjust the current setting and correct or calibrate that like if your set at 1.6 set it at 1.2? our excess boiler hot water slug feeds to the DHW coil so we don't have that problem. i'm not sure you'd accomplish anything with what you're saying except have a lot of short cycles of low temperature boiler firing something i've always been told is a bad thing for a non-condensing boiler.
    Last edited by Blue RidgeParkway; 11-18-2008 at 01:44 PM.

  9. #19
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    Default Re: Weather Response Heating Control System

    Quote Originally Posted by Blue RidgeParkway View Post
    i'd have to watch the show again. in the meantime if you're grossly overshooting room temp at your thermostat couldn't you adjust the current setting and correct or calibrate that like if your set at 1.6 set it at 1.2?
    Yes, I'd like to watch this episode again too. I saw it twice last weekend just so I could catch the name of the manufacturer.

    Yeah, it's not a huge problem for me... once the boiler water is initially warmed up, there's not too much overshoot. And by knowing when it will overshoot, I just manually turn down the thermostat after it runs for a while.

    The device in the program was touted as an energy saver when used all season. After thinking about it, it may not be as effective on my older system. Right now my system only reaches full operating temperature (180) on really cold days. On warmer days, the boiler water may only get up to 140. The mass of the water and the cast iron radiators really dampens things quite a bit.

    On newer systems that always run up to 180, with copper fin baseboards, less water mass, quicker response, and pumps, I can see a Tekmar system like this being a huge energy advantage.
    Last edited by sparky672; 11-18-2008 at 02:08 PM.

  10. #20
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    Default Re: Weather Response Heating Control System

    sparky,

    here is a link for you.

    http://www.heatinghelp.com/heating_howcome1.cfm

    i'm suprised you don't have a bypass by now.

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