how does WWSD work?

R. Kalia

In our area, warm days (say 80) followed by cool nights (say 60) are common in summer. With built-in reset controllers or add-on Tekmars, would warm-weather shutdown (WWSD) cause the boiler to turn on and off every day? This is not really needed, because of the lag...house may cool down a bit below 70, causing the indoor thermostat to call for heat, but it quickly warms up during the day without the boiler's help.

One could stop the boiler starting by setting the WWSD threshold low (say, at 59), but that doesn't work since the house does need heat if the temperature stays at 60 all day.

What might work best is a "sluggish" or averaging WWSD, such that the heat will come on only if the outdoor temperature stays under 65 for over 12 hrs, or under 60 for over 6 hrs, something like that. Is that how these controllers function?

Ken_8

Well, you can't really do that either...

Because sun loading on one side will make it hot and a zone on the shady side may need a litle boost and all the variables will make you nuts.

If it's summer and warm - turn it off!

The first day you think you'll need heat - turn it back on.

KISS method - all the way.

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R. Kalia

What Would Satan Do?

I do understand that I can do it manually, but there IS a feature called WWSD on many outdoor reset controllers. I didn't add that, Tekmar or whoever did. Are you telling me this feature does not work properly and should be disabled?

ALH_3

Limit

WWSD just keeps the system from running if it's too warm outside to require heat. It's just a limit, most likely to save fuel in the summer. If none of the thermostats call for heat during the night nothing (except DHW demand) will fire the boiler even if it's not on WWSD. Turn down the t-stats in the summer and there is no problem. :-)

Wayco Wayne_2

The WWSD

should only be used to enable the heating system. There should be some kind of indoor feedback like a thermostat or sensor that would initiate the heat. I usually set mine at 68. WW

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Ken_8

It doesn't overcome what you

want it to.

Nothing does what you want it to. Not even them fancy-pants euros have a cure for sun loading on south facing glass (:-o)

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Paul Pollets

Sure they do...

Air Conditioning

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Jim Eastman

WWSD

That is all correct and good---unless you have a constant circulation zone with panel radiators, for example. The way that I set the WWSD on my own system (with Buderus panel radiators on constant circulation with outdoor reset) is to set the WWSD for 60 degrees in the winter season and 50 degrees during the summer seasons. That way, I don't have the heat kicking on on a cool Colorado summer morning when I have all the windows open and the whole house fan on to cool the house for the 85 - 90 degree day that is looming on the horizon.

Jim Eastman
Precision Plumbing
Boulder, CO

Unknown

WWSD

basicly will disable the system from firing if the outdoor temperature rises above the WWSD setting. The outdoor sensor should be placed in a location where no heat gain (solar or thermal) will be encountered. This spot would always be cooler in ambient temperature than the south or west side of the building that is encountering the solar gain. This way, solar gain will only affect the heated space and not the ambient air surrounding the outdoor sensor.

With the 370 and 371 House Controls, the WWSD would be overridden if any of the indoor RTU's drops below the WWSD point. With these the WWSD is the same as the highest RTU setting provided all of the zones are satisfied. Our EC5000 control operates in an identical manner as the House Controls.

Glenn Stanton

Burnham Hydronics

Ken_8

You euros,

think of everything (:-o)

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R. Kalia

precisely

> That is all correct and good---unless you have a

> constant circulation zone


Precisely. This is why I asked.

Weezbo

WWSD is the candidate for SPace conditioning....

shut the boiler down,open a zone snap goes the relay on goes the heat sink field recirc,snap goes another relay the water is continiously circulating in the house at low temp using the same header you already have,only difference is, the boiler is off .Zoned Off. what else could possibly be bettern that? thats My Story an im stickin to it:)........now if i can get those i- Series...