# Aquastats for water heaters



## HackWork (Oct 2, 2009)

I've wired aqua stats to hot water circulators before since it was 120V, but the plumber speced and provided both of those items.


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## drewsserviceco (Aug 1, 2014)

All it does is call for the heater to run if the water temp is to low and turn off when temp is reached. Most are just a probe held on with an aviation clamp, some might have a well the aqua stat threads on to. Really just a set of contacts so wiring should be easy. Other than matching the probe style just make sure to get one in the operating range you're replacing.


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## MTW (Aug 28, 2013)

In my area it varies, sometimes the plumber does it all, sometimes he does the low voltage and sometimes we do the whole thing, line and low voltage. Usually we never supply those components, we only connect them. 

Is this indirect unit supplied by a circulator or zone valve? If it's a circulator, all you need is a one zone circulator relay. If it's a zone valve, all you need is a 24 volt transformer. The aquastat on the tank will turn the relay or zone valve on and off.


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## WronGun (Oct 18, 2013)

This is a replacement job but with not the exact same model numbers. The wiring is existing from what I've been told. A Honeywell L4080B-1352 was recommended. Directions say to drain the tank and use an pump. This is a client of mine I'd like to do the job but I don't want to leave him without hot water on a Saturday. Do you think this is a mater of relanding wires on the new switch? Do they simply attach to the water tank ?


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## drewsserviceco (Aug 1, 2014)

The system is closed. I wouldn't drain down the boiler. There's a way to do it so that you might get one glug of water as you take the old one out and thread in the new one. 

Obviously I'm not there and your comfort level will dictate what you do.


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## nrp3 (Jan 24, 2009)

It helps to have a few friends to call when you do this kind of work. It may be available at Grainger. Recently got an account at one of the plumbing supply places so I had a source of Kohler generators. It helps to work with a plumber when doing heating so the proper settings are established and that the proper sequence of events happen at the right time. I wire it up, but he makes sure it works properly.


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## WronGun (Oct 18, 2013)

nrp3 said:


> It helps to have a few friends to call when you do this kind of work. It may be available at Grainger. Recently got an account at one of the plumbing supply places so I had a source of Kohler generators. It helps to work with a plumber when doing heating so the proper settings are established and that the proper sequence of events happen at the right time. I wire it up, but he makes sure it works properly.


I guess the plumber is installing everything I just need to go and land the wires in EMT


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## nrp3 (Jan 24, 2009)

Good time to ask questions. I like doing boilers and HVAC wiring.


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## WronGun (Oct 18, 2013)

nrp3 said:


> Good time to ask questions. I like doing boilers and HVAC wiring.


A controller is already there. I'm just taking the 2 wires off the old controller and landing them on the new controller....


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## MechanicalDVR (Dec 29, 2007)

Most aquastats like this are mounted on a dry well and don't need any tank draining done. You do need to fill the well itself with heat transfer paste provided with the new aqua stat. With an indirect storage tank the aquastat typically just brings on a pump relay but a 40 series controller is for linevoltage switching so who knows? Hit me up if you have any more questions on this type thing, spent years with this stuff.


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