Best Of
Re: Retirement second thoughts
Im in the same boat. It does become harder to stay in the loop when you’re not in the game every day. Mainly putting your hands on the newest and latest stuff.
Sites like this will keep you up to date on the industry, both the newest and the oldest equipment out there gets dragged across HH. It is a unique site in that respect.
Plenty of opportunity for freebie work for neighbors and friends to keep the tools from getting rusty.
Pick a hobby or two. I help out with a local dog rescue group, you get two wins. You and the dog. Also the therapy dog group that my sister is involved with.
The box stores around me are staffed with semi-retirees, many work 4 hour shifts a few days a week. My lumber guy at HD goes in early to restock, leaves at 10:00 AM
You gotta keep the body moving, or lose it.
hot_rod
Re: Do two wire thermostats short the thermostat wire when they turn on?
Hello In_New_England,
I would do it something like this.
Say you want the boiler the run for 10 minutes every 8 hours when the temperature outdoors is less than 32 degrees Fahrenheit. Mostly independent of anything else. (the times are just an example)
If the boiler's normal thermostat has activated then the microcontroller box delays its call by 8 hours (or what ever you want).
The microcontroller would ignore a call from itself (relay closure).
So above 32 degrees Fahrenheit or if the boiler's normal thermostat calls are more frequent than 8 hours the microcontroller will never generate a call for heat.
Fairly simple program for an Arduino or the like.
What is the maximum AC input voltage of the HCPL3700, I could not find it in the data sheet.
The temperature input can be anything you want a temperature switch, Analog or Digital. If you use a sensor that reports the actual temperature to the microcontroller (analog LM34, digital DS18B20, etc.) the frequency of the boiler running can increase as it gets colder outside.
I would probably buffer the relay coil with a transistor and don't forget the diode across the relay coil.
109A_5
Re: Do two wire thermostats short the thermostat wire when they turn on?
HCPL3700
Going by the symbols in the HCPL3700 circuit, D1 and D2 appear to be Schottky Diodes (low forward voltage drop). D3 and D4 seem to be Zener Diodes (Limits the input Voltage). You may not be able to apply 24 VAC directly to pins 1 and 4, you may need (at least) a current limiting resistor. If you use this device I would use the DIP package and install a socket.
Edit: Also look at - Application Note 1004
You will need to filter it too unless your microcontroller's code can deal with the microcontroller's input pin switching on and off at a 120 Hz rate during boiler inactivity.
109A_5
Re: Seeking feedback on new TRV
Re: Seeking feedback on new TRV
I agree, those are beautiful valves. I would've padded the wrench with a bit of cloth when tightening it to prevent scratching. The video is well done but there are a couple of minor errors. At 1:17 Teflon® is spelled as "Tefflon". Perhaps this is a difference between British and American English but at 2:31 and following the heating appliance supplying steam is called a "furnace". Here is the USA a "furnace" is something used to heat air. A "boiler" is used to heat water to steam. I'm not trying to criticize but trying to help you make a better product.
CLamb
Re: Home Boiler System - Need help sizing boiler circ pump
Get rid of those dielectric unions as there is no electrolysis on closed systems. After awhile, they freeze up and you can't unscrew them. On domestic systems, they also accumulate mineral debris.
I prefer a ground joint union.
Re: Triac speed controller for circulator motor
If you want to vary the speed of an ECM circulator you need to get one designed for that. A Taco VT2218 variable delta T circulator or a variable delta P circulator like the Taco Viridian or Grundfos Alpha.
Re: Dual 40 gallon versus single 80 gallon water heater
Hi, If looking at two tanks vs one tank, I'd go with two in series, valved for isolation and bypass. Even with perfectly balanced plumbing, it will in time get unbalanced due to corrosion or scale. I like the two tank concept with HP in the lead position. Reminds me of two tank solar thermal. I attempted to be an early adopter of a 120 volt HP, but could not get the thing to behave. Wound up going back with propane. Hopefully the industry is maturing. 🤔
Yours, Larry
Re: Efficiency of an indirect water heater
Hi jesmed1 -
Look up HOYME Combustion Air Damper or local equivalent.
Doug_7