Aquastat vs. Setpoint Control

PB_2

I will be having a DHW tank added to my Buderus boiler. I WILL NOT be doing this myself, but I am trying to spec-out the equipment I want installed.

I have a GHW conversion. The boiler is a Buderus G-234 gas boiler with 153,600 output. It is controlled with a Tekmar 260 outdoor reset with DHW control. The boiler is now piped primary secondary with a Termomix Thermic bypass valve and a 40 gal buffer tank. The boiler was oversized and was short cycling and condensing. This piping was done based on advice from a previous post. It no longer short cycles or has a condensation problem. Thanks everyone for the help!

I am going to have a Buderus ST-150 (40 gallon) indirect hot water maker added to my system. I am not sure if there is a benefit to using a Tekmar setpoint control or a Honeywell aquastat. Anyone have any opinions?

Any recommendation for a circulator for the DHW system?

Any advice always appreciated.

PB

hr

I've found

set point controls, with thermistors sensors, to be much more accurate than a cap tube aquastat.

Most have digital readouts, these day, which is easier to read at a glance. And they all have adjustable differintals dials or programs. Generally they all can be powered with 240, 120, or 24volt on the same control.

I wouldn't recommend a setpoint to replace a factory installed aquastat, however, but for accurate temperature control from distances up to 500 feet, look into a setpoint.

Honeywell has them. Goldline has a very inexpensive one, SP-30. Find them in Graingers catalog for around 60 bucks, with optional digital readout. HeatTimer, Ranco, Johnson Controls, and many others. RTI has a clever one with a 100 degree diff spread available!

hot rod

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PB_2

Set Point Control

The Buderus tank does not come with a factory installed aquastat, so I will probably go with a set point unit.

Thanks for the information.

Patrick