Question on install of hot water garage ceiling unit heater

DIYCharlie

I am a DIYer installing a Modine horizontal hot water ceiling unit heater in the garage. The water will be supplied through a dedicated zone. I was going to use a Honeywell round (2 wire) t-stat like the house zones use. Unfortunately, I hadn't been thinking about what tells the fan to come on, but I am now.
The manual doesn't provide much guidance. The label on the connection box on the unit says something about a line voltage t-stat. Appreciate any enlightenment on how this has to be set up.
Thanks much.

Mad Dog_2

The Aqaustat...Mad Dog 🐕 

Big Ed_4

The thermostat turns on the pump . Use a "B or reverse" aquastat ,which makes on temperature rise, mounted on the return pipe , The B turns on the fan when unit heat up . Normally run line voltage

DIYCharlie

O.K., I just started looking at aquastats for the fan. Seems like the strap-on type should work, correct?

hot_rod

A simple snap disc type on the hot supply at the heater

you can get adjustable of fixed temperature there are are limit and fan version

the fan version makes in temperature rise

Rickoo

Recently installed one of these. Works fine. Not sure if it was the best option.

https://www.supplyhouse.com/Ranco-ETC-111000-000-Single-Stage-ETC-Temperature-Control-w-8-Sensor-120-240V-Input

pecmsg

Does this garage see below freezing temperatures normally?

EBEBRATT-Ed

@DIYCharlie

Most use the thermostat to start the circulator and or boiler depending on how the boiler is operated. Then use a strap on aquastat L6006C to power the fan when the supply pipe gets hot although there are cheaper options such as what @hot_rod posted.

If the garage can get below freezing, then that has to be considered. A heat exchanger off the boiler with glycol is the best but it gets pricy with everything you need.

Big Ed_4

Hot Rod , why on the supply pipe ?

mattmia2

You can use an aquastat on the pipe or you can use a relay controlled by the thermostat. The relay is probably cheaper but it will blow cold air until the hot water gets there from the boiler. Could use a time delay off the thermostat to avoid the cold air.

Or you can control it all off a Crestron processor like i did.

Rickoo

Yes, why on the supply? I have mine on the return just off the heater, although not really sure why. My thinking was if the return is hot the unit would have to be, and only then have the fan come on.

hot_rod

I suppose it would depend on the temperature setting of the the switch
If you put it on the return, you might use a lower temperature setting

First you need to decide on the SWT
ODR would complicate that. 

Myson kick heaters come with a 120- 105 clip on switch

The switch would need to work down to the lowest SWT, however that is controlled

Electric water heaters and many furnaces are controlled with those reliable , inexpensive snap disc switches, they work well

Big Ed_4

I always install them on the return and set them to 120* , so it would not blow cool air .

DIYCharlie

I bought the below strap-on control that will make on temperature rise.
The garage will only get below freezing if utility power goes out and my generator doesn't work. I'm not using anti-freeze, so in that situation the house will also be freezing, and I suppose I will be scrambling to drain everything and sitting in front of the fireplace.

Thanks for the help all.

Johnson Controls A19DAC-1C