Best Of
Re: 99-year-old reliable (?) boiler - what would you do?
That boiler looks great. And there are very few moving parts that make it operate. Mainly the limit control has something that expands and contracts as the temperature changes, As does the original thermostat (if you still have that) and the gas valve has a coil that is an electro-magnet the opens the valve when everything is cold and closes the valve when things heat up. That valve coil makes the main burner gas turn on and off.
Any new equipment will have electronic timers for ignition and combustion, circulator pump to move the water that needs no pump in your existing boiler, a combustion fan, and all sorts of limit and pressure switches to monitor when the gas should burn and when the gas should stop.
By the look of that Honeywell Gas Valve, you have one of the safest standing pilot controls available. That valve is replaceable with standard off the shelf parts you can source locally of on amazon.com.
So your homework is to take the cost of the 2 or 3 free estimates for a replacement boiler and compare it to about 30% of your annual gas usage. (the gas usage for winter only, not the laundry, cooking or hot water). To get that number for heat only use your lowest gas bill and multiply by 12. Call that number X. then take a years worth of gas bills and figure out that total. Call that number Y. Now deduct X from Y and that will be your heating gas usage bill. Multiply that number by 0.30 and call that S1. That is what you will save with a new heater in one year. Multiply S1 times 10 and get a total of 10 years of savings. (That is savings not adjusted for inflation). Compare your 10 year savings to the cost of the new boiler. If the boiler is a lower cost, then replace the boiler. If the boiler is a higher cost, then keep the old boiler.
I selected 10 years because most new boilers will last between 17 and 30 years with an average of about 20+ years. So that leaves you at least 10 additional years after you have recovered your initial investment to actually get a return on your investment.
Unless you only plan of being in your home for a few years…. that will skew the whole thing
Edit: The savings of 30% are conservative. I know from experience that you will save more than that. I have done that job with both Atmospheric cast iron boilers and with the new modulating condensing boiler. The savings will be more like 40% with the Cast Iron, and closer to 50% with the ModCon. The problem is that the job is so expensive between asbestos abatement, scrapping the old iron from the site, and building the proper near boiler piping for the replacement, It ain't cheep! If you are into DIY, then you are better off with a new boiler. If you are going to pay retail, then you need to seriously look at the numbers.
Re: Back for its 69th consecutive season...
Keep up the TLC and that will be going long after any of us are around — let alone the modern equipment.
Re: Can this install be salvaged?
This is an alternate that uses one less circulator.
Re: Can this install be salvaged?
Why do so many seem to recommend thermostatic mixing valves? I despise them. If the boiler is operating on outdoor reset all you need is a proportional mixing setup to mix in a portion of the water that is returning from the zone. I have done it on many systems. For consistent operation each zone needs its own close tees and bypass valve so that there are no pressure differences that could affect flows depending on how many other circs are running. Doing it proportionally will allow you to still have an outdoor reset temperature instead of a flat temp. Will try to post a drawing.
JMWHVAC
Re: Help running new zone and adding to other
Depending on how much repiping you want to do. A single 1" purge ball valve like shown and you could eliminate the individual purge valves, leave the ball valves in place to isolate the various loops for purging.
Or just use a 3/4 Webstone where you add the new zone. The cost of these makes it a no brainer instead of a multi valve multi fitting assembly.
Yes just refill to leak test. Doing an air test first complicates the procedure. If you have a leak it will be right in front of you.
Webstone has sweat, thread and press options.
you go the press route, sand the pipe, remove the burr, it is very rare to have a leak.
Assuming you press all the fittings :)
hot_rod
Re: K-Flex Titan
"It might he a long shot, but would you happen to know the part number for the High Temp epdm version"
I've tried to find this out before without any luck. The people who install solar hot water systems should know since it's the insulation type they use for the line sets.
Waher
Re: Preferred location for air separator and expansion/compression tank in primary / secondary systems
I would use a good air sep at the boiler, the vent pipes up to the tank fitting
The Caleffi Discal has an npt adapter fitting for remote venting the discharge air
hot_rod
Re: Preferred location for air separator and expansion/compression tank in primary / secondary systems
If using a conventional tank, you can only have one air separator. If you install a second one, The air from the tank will gradually be reabsorbed into the water and the second separator will vent it to the atmosphere. You will eventually lose the air charge in the tank, and start popping the pressure relief valve. WE've seen this problem numerous times, along with its cousin….people keep bleeding air from radiators ( which make great air separators) and the conventional tank loses it air cushion. Air tends to end up in the radiators because the air separator is missing or poorly located.
