Sizing Boiler Using DOE Booklet 25 Years Ago - What Went Wrong?

MikeL_2

I do get accused of repeating the obvious; only because I don't want it to get overlooked and I think it helps to raise awareness levels.

I appreciate this forum the most for it's wide ranging discussions. I'm certain there's value here for someone's future challenge and always an opportunity for learning.

Thorough trouble shooters try to identify all contributors to a particular problem and eliminate them in an orderly process. That happens here frequently on Heating Help, often as a team effort. Sometimes solutions can hide in plain sight.

EdTheHeaterMan

A picture is worth a thousand words. From the original post:

My original 120K BTU gas boiler needed replacement (it was leaking). (Was the old boiler a Hydrotherm with an Electo-zone control that was attached to the end of the manifold pipe) I used a booklet I think was distributed by Dept. of Energy. I calculated about 60000 BTU for 0 deg design outdoor temp. I also added up all the baseboard in the house. That was 111.5 ft. Using a Slant Fin chart for 170 deg baseboard, 550 BTU/hr gave about 61000 BTU/hr. Of course, 25 year old baseboard might be less. Still, 60000 BTU/hr heat loss still sounded good. I didn't know how to use the 1.4x oversize factor. I figured it meant multiply 60000 x 1.4. giving 84000 BTU/hr input. I wasn't going to go that low. I thought what I needed was a boiler with an IBR net of at least 60000 BTU to the baseboards. I found a Utica boiler with IBR net 72000, which was a 100K BTU unit. (never said what year the Utica boiler was found) Trying to find a contractor to put in a smaller boiler was challenging. Three contractors came and went after they couldn't change my mind. I think all the contractors in my county bend their elbows at the same watering hole. That's why out of the next ten or so contractors I called afterwards, only one responded. That contractor actually quoted a 100K boiler. I think he knew what was going on, and was starving for business. The experience with the installation was not good. (I must agree by the look of the photos of the boiler job) Anyway, the new boiler kept our bedroom at 62F when at 0-10 deg outdoors. Original boiler was 68F. The bedroom is the only room with 3 exterior walls. The rest of the house was also cooler than with the original boiler. The outlet temperature of the new boiler is 180F, same as the old boiler. Using my infrared thermometer on the zones, I noticed that the biggest zone in sq. ft. had a 30 deg drop from outlet to return. (that would be from the original zone valves from the Hydrotherm system) The internet had some old rules of thumb, one of which indicated a 20F drop is the goal. I took matters in my own hands, and replaced the Taco 007 that came with the Utica, with a Taco 0010. No change. (now you have a B&G 100 that also would offer no difference) I then replaced the original zone valve on the biggest zone with a full port Honeywell valve. (Actually you have Honeywell V8043E valves , not full port but with a higher Cv than the old Eletrozone valves) Success, got the 20 deg. drop. Rest of house was warm enough except bedroom. The house has three zones, so I replaced the other two zone with full port, hoping it would help the bedroom. It didn't. That's because even with small port valves, the bedroom zone was able to maintain a 20F deg. drop. The three zones are simple loops. I believe the rooms closest to the boiler on the bedroom loop have too much baseboard since they get too hot. If about 4ft. of baseboard was moved from the near to boiler rooms, to the bedroom, it could get back to 68F at design temp. of old boiler. Do you agree? (Maybe, maybe not) I think the old boiler, having a larger heat exchanger, delivered more BTU's to the baseboards while coasting after firing. That compensated for the wrong distribution of baseboard on the bedroom loop. I don't know if I know what I'm talking about. (Not sound logic on this point. Poor piping design and not addressing that problem when the new boiler was installed many, many years ago) Help!

StanKatz

If you read the subject of the post you would know i bought that Utica boiler more than 25 years ago. In fact, It was installed in 1991. It's 33 years old! It looks worse for wear, but it's still hanging in. Utica is still making boilers in New York although its Utica, NY plant was closed in January. All its boilers are now made in Dunkirk, NY

EdTheHeaterMan

And you are just getting around to asking about it in 2024?. I think most of us are trying to solve a more recent install problem. The Hydrotherm was replaced by a Utica. then you lived with a problem for over 25 years. and you are asking what went wrong.

Piping design went wrong. If you want to solve the problem, put the pipes together the right way. And if you cant afford the put the pipes togetther the right way then move the thermostat and see if that works. or live with it for another 10+ years until someone else needs to replace the boiler

StanKatz

The name Hydrotherm rings a bell as the name. At the end of the return manifold is a wiring box ( I reused it) that says "Master Control Panel"…"Trimline Pack" . I do remember that the old boiler was a steel boiler, if that helps. I'm confused about the zone valve. I thought the contractor installed Honeywell small port zone valves. That's why I bought what was offered as a full port one off the internet. I got the temp drop to go from 30F to 20F with my install. Are there "tiny" port Honeywells? If not, why was I successful with the sway?

StanKatz

I'm sorry I contacted this forum so late in life with my heating problem. When I experienced the problem in 1991, I dealt with it as well as I could without the existence of the internet and this forum. My wife and I were much younger (obviously). We are now elderly, and the cold bedroom is more of an issue (especially to my wife), and the internet and this forum now exists. So I do hope you can forgive me. I am extremely grateful for the help extended to me.

StanKatz

I'm beginning to look like an idiot here. I post comments meant for one author in the original subject thread, and the comments wind up in a, much shortened, derivative thread. The derivative thread has my original post edited by EdTheHeaterMan in it. I made a somewhat snarky response to MaxMercy regarding my old looking boiler, and it wound up as a respone to EdTheHeaterMan! EdTheHeaterMan is the last author I would ever want to offend. Help!

EdTheHeaterMan

Not offended at all, Just took some time to get the context of the issue. The way it was presented sounded like you had an old boiler from 25 years ago that was sized by an old IBR calculation form. A few years ago you had the Utica installed to replace the 25 year old boiler because it leaked a few years ago.  I find this happens a lot, that is why I like to draw diagrams so I get the big picture.  And it only took 4 days this time.  Not bad for this old guy who is losing his marbles. I remember taking 9 months to get a DIY to get the picture when rewiring his air handler to accommodate a Hydronic hot water coil in his ductwork for heating.

Now with the full picture, it makes sense. With the advancing age, my legs are always freezing. I set my air conditioning thermostat to 78° and my feet are still freezing. When the girlfriend comes over, she needs to set it to 72° and I need to wear sweats to keep my legs from hurting. (what we do for our women).

So, the lowest cost thing to try is the thermostat in the cold bedroom idea. Do you know anyone that can do minor handyman jobs? That will be the easiest thing to try first. But at this time of year you will not know how effective that change will be until next December when it gets cold again. That will also give you more time to allocate some money and get estimates to repipe the boiler so all the energy that boiler makes can get to the rooms. As far as getting the large zone split in half(ish), that will be something that you can decide to do later. The Zoning Made Easy text book covers the problem with zone valves causing a restriction on page 17, HOW TO SIZE THE ZONE VALVES AND THE CIRCULATOR. It says that the normal 4 gallon per minute with a 3/4" pipe will be restricted to 3 GPM.

The old Hydrotherm boilers that were installed with that master control attached to the pipe used Electrozone valves that operated on DC voltage. Those valves also have a low Cv. so they restricted the water flow as stated on Page 17 in the textbook. When you removed those valves and installed the Honeywell valves with the higher Cv, the 3 GPM increased closer to 4 GPM, because there was less restriction. But if you look at the actual internal guts of the valve you can see that it is not full port, but full port or not the Honeywell fixed the issue in the large zone.

Since the smaller zones did not need more than 3 GPM, swapping the valve did nothing to solve the cold bedroom. The only thing that can solve the cold bedroom will be to add more radiators in that room. I say this because the way your system is piped, swapping the supply with the return will be a larger project than I originally thought. 

Now when you add more radiator the the bedroom, you will need a plumber to drain the boiler, then add the 5 feet of radiator, then check for leaks, then fill the boiler and purge the air from the system.

If you decide to redesign the near boiler pipe to make the two 3/4" zones for the basement and the bedrooms get feed by a 1" supply pipe, the you will need a plumber to drain the boiler, then add the 1" pipe, then check for leaks, then fill the boiler and purge the air from the system.

Later if you feel the needed to replace the expansion tank and install it on the supply piping with the circulator pumping away from the expansion tank in order to eliminate air problems in your system, you will need a plumber to drain the boiler, then move the pump and replace the expansion tank, then check for leaks, then fill the boiler and purge the air from the system.

You can see a recurring theme where you are paying for a plumber to drain the boiler, then do a repair, then check for leaks, then fill the boiler and purge the air from the system. Four of these things are common to all the other jobs. and the time it takes to do those 4 jobs is not cheap. That is why I recommend doing all the wet upgrade jobs at the same time. Then you only need to drain the boiler, then check for leaks, then fill the boiler and purge the air from the system once. That will be a savings of thousands of dollars when compared to getting each job completed separately.

StanKatz

Nice! If I can finance the job your instructions seem complete enough to show to a contractor, along with your piping schematic. I appreciate your kind expert assistance in this matter.

MaxMercy

https://forum.heatinghelp.com/discussion/comment/1801326#Comment_1801326

I'm not offended either (not my nature) and you're not looking like an idiot - but I honestly thought this was a recent install using a 25 year old booklet which is why the picture of your boiler surprised me and others. The only way I would be offended is if you told me my Carbonara wasn't very good..

Regarding the thermostat, you can try relocating it to a location you think might help with a some hookup wire and just tape the wire out of the way so you or your wife don't trip on it. If that fixes the problem, then it would be worth the money to have it professionally moved if you can't do it. If it doesn't help, you'll have eliminated that possibility at least and saved that money it would have cost to try.

Mustangman

Cut it out and start over. Not kidding. That is a horrible job that will not consistanly perform. Bull headed tees are not good piping practice. The water will hit the back of the tee and god knows which way the water will go. Each zone should come off of an 11/4 supply header as shown in the drawings above.

I know its going to cost you money and that is a shame. IMO there is just too much wrong to save what you have. You said the installer was slow and hurting for money? There is a reason…

Good Luck

Steve