Help me understand the relationship between my heating coil and my boiler

seandempsey

Hello -

This question has been hard to Google, so hopefully I can even aticulate it.

My boiler is seen below, it is an old battle-axe from the 1960's. Presently it is how I heat my Maine home with 2-pipe steam radiators (where I have learned from this forum, are even possibly considered a "vapor" system), and it also has a hot water heating coil that runs through it.

I only appear to have 1 burner that fires and is plenty loud, and during the summer when the heat is off, it just turns on a few times a day to keep the domestic hot water at where the aquastat is set.

My questions are:

First, if I were to say let the hot water in the shower run for 2 hours, would I feel my radiatiors heat up since the burner is agnostic to what it is heating, and heating the DHW coil for 2 hours would also cause steam to be sent to the radiators since it is not 2 separate systems?

Second: I had a second question but can't remember.

Here's the setup!

nde

The aquastat will cut the burner in/out based on temperature limit for the hot water coil. So even if you run 2 hours straight shower the burner will not run continuously and the rads would get lukewarm at best....but sounds like some sort of hypothetical thinking? Or maybe you have teens???????

seandempsey

Oh good point on the aquastat, I didn't think about a high-temp cutoff as well.

It's not purely hypothetical, I am trying to understand what will happen come the day that the system is no longer able to be maintained or repaired, or other technologies replace it that are more effective. I have had 4 different heating/plumbing service folk look at it over the last 18 months for different needs and I have asked about the future of options.

Right now, it is my only heating system, which feels risky. So I am trying to form a long-term plan on what the alternatives are for heat (in Bangor Maine), and then hot water. And if I don't do it all at once, I will be breaking up the system that has been in place for a very long time. I had suggested to me a heat pump for the hot water, which would take it off the coil and also mean that my boiler does not operate during the summer months - which introduces the period of time where I would need to "summerize" the boiler and radiators since they will not have any usage from May-Oct. I have also had recommendations for doing heat pumps for additional heating (and summer AC and dehumidifying), which would then make my usage of the radiators less, but I still need the hot water from the coil.

Or, I do a plan that takes me off everything altogether, but I don't think I can survive without the radiators and only heat pumps for heat, so in a way I may be stuck with the boiler until I do a seignificant and extreme complete renovation of the heating of the house and DHW, which is then a whole other issue including being told that the service people who looked at my boiler said they aren't sure if a new boiler could be installed to service my radiators given the systems age and complexity.

So for now, I just want to understand more and keep looking at future plans of how to keep the house and water hot in the event that my boiler/radiator system someday is forced into retirement.

nde

Heat pump is useful for summer ac and cooler temperature supplemental but you will need oil/gas boiler for winter months, as you know it hit 15 below a few times this winter.

Is there a natural gas connection available to you? If so I would run the gas to the house and consider swapping the boiler to NG sooner than later. Most contractors and persons here will tell you to get rid of the coil and go to standalone hot water like wall hung or at least get a storage tank. But the fact is in BGR you are looking at 6-7 month heating season where essentially the coil is providing hot water for energy already being used to make steam. I use a coil for hot water with no stand alone tank...in summer my gas bill is about 30/month which includes 15 surcharge and we cook with gas, so say my hot water cost 10/month or even if double or tripled based on gas prices 20 or 30 x 5 or 6 = 50-150 for summer hot water....you will never see ROI the wall hung on demand that no doubt the contractor recommended.

There are no steam experts in Bangor that I have found but there are contractors who will install the system as per manual specs so long as you put it exactly in writing. Point is you are going to need a boiler, steam makes the most sense as cost to convert to hot water is high.

If oil is all you have get a burnham triple pass megasteam installed. If you convert to gas get a peerless or weil mclain atmospheric or you can also use a wet based oil boiler fired with power gas burner. The WM gold oil works well for this and will be more efficient but louder than the atmospherics.....either way get Dans book or borrow from Bangor Library to learn more about your system and to advise the contractor on how you expect any new boiler to be installed correctly as per manual specs.

Jamie Hall

Until the boiler gives up -- which it will tell you by leaking -- stick with what you have and invest, if you like, in reducing the heat losses from the structure.

If you were to do a change now -- I'm not really good at predicting the future -- I'd recommend a new oil fired boiler for the steam system. As has been noted, steam people are kind of thin on the ground in Maine, for some reason, but any competent and somewhat open minded plumber can, with the aid of the boiler manufacturer, do a good job of installing a new one. There is a trick to sizing it -- but we can help you with that.

As to the hot water... hmm. Some folks really like heat pump hot water heaters, and they are very efficient -- provided you don't have larger relatively short demands, like two or three showers in a row. Then they aren't. They also are not cheap. Three other approaches -- besides the hot water coil type you have now -- are an "indirect" hot water tank, which is heated by the boiler but stores hot water like a regular water heater would, and a stand-alone hot water heater, which can be fired either by gas (common) or oil (not common, but very satisfactory) or electricity (expensive to run, cheap to buy). There are advantages and disadvantages to each approach. The third is tankless hot water heaters -- but for that you have to very careful of you peak loads, and you almost have to have gas.

EBEBRATT-Ed

I would budget for a new boiler. I would install a Cast Iron steam boiler properly sized with an indirect tank for DHW. You will get more hot water with a slight increase in efficiency.

That being said those American Standard boiler were very good boilers but that is probably late 1960-1970 boiler.

It may run a long time yet but if something fails on it you want to be ready.

Start with measuring and calculating your EDR radiator load in preperation for sizing a new boiler.

Anything you can do with insulation, weather stripping, doors & windows will help and save for a new boiler.

I see you have an automatic water feeder. I would get a water meter installed to see how much water is being added and then make your best attempts to tighten up the steam system to prevent water loss.

Do you have any steam returns run under the basement floor?

seandempsey

Thank you nde and Jamie, I am adding all this information to my notes. It's going to be a big orchestration when it all happens.

I actually had been told that there may not be a boiler replacement for my system available, so seeing the "burnham triple pass megasteam" is great to know they exist. I have talked to some folk who I reckoned didn't know what they were talking about, including running hot water through my system instead.

Regarding natural gas - I do not have service to my house, but it is on my street. I could get it if I had 2 appliaces that need it.

As mentioed in a post from last November, I did get my attic spray-foamed and now it is going to be another 800 sqft of living space with 8 foot ceilings, 30 inch kneewalls, and a 12:12 pitch on the angled ceiling portions. Not sure of the cubic footage, but just whatever it would be for a rectangular prism, subtracting the angles of the roof.

So far, I have let the heat from the house travel up to the attic, and where before the space was below freezing (or 108F in the summer), it's been locked in at about 60F with no active heating, just the convection of the lower floors, and then when I close the attic door and the hatch, the attic will maintain its temp, so that thing is locked-in, I am not sure I need heating for it in the winter, but in the summer I am guessing the home's heat will make me need some cooling up there, even if the heat from the sun and roof doesn't make it through the foam.


- BEBRATT-Ed: My steam returns all run down the walls and then into the basement, it's all exposed joists down there, about a 6 foot height to the basement ceiling. Everything is exposed, you can see a ton of pictures here in a previous post: https://forum.heatinghelp.com/discussion/185585/better-balancing-1st-and-2nd-floor-with-2-pipe-steam-1-zone

EdTheHeaterMan

I believe that you made good decision to come here for relationship advice. If you let the little things like this fester, they can grow out of proportion and the relationships will only get worse.

Operating the burner for DHW only will never make steam, so there will never be any heat released into the radiators. the water does not go up that high... so no heat transfer will ever get there.

I can't help but notice that your boiler still has the original oil burner. Depending on the type of air handling parts on the end cone and the nozzle assembly, you may not be burning the oil as efficiently as possible. If I recall correctly your ArcoFlame oil burner is not of the flame retention type. Here are two oil burner nozzle assembly illustrations from the Wayne Home Equipment Co. (Wayne Oil Burner) that illustrate the difference between the standard gun burner and the Flame Retention burner.

By looking at the part number 17 and number 22 on each illustration you can see a difference in how the air flow is sent to the combustion chamber. The more efficient Flame Retention air handling parts produce a hotter flame with substantially less excess air. This design can reduce your fuel usage by 15% compared to the standard gun burner you have now. See if your oil dealer or service company can install a new combustion chamber (or chamber liner) and a Beckett AFG or Riello oil burner. They will lower your oil consumption.

EdTheHeaterMan

EdTheHeaterMan said:

I believe that you made good decision to come here for relationship advice. If you let the little things like this fester, they can grow out of proportion and the relationships will only get worse.

This should at least get a couple of LOLs

seandempsey

Interesting. I have the original user manual for the oil burner, it was still down with the boiler. I also have the manual for the boiler, it's a 1968. Classic stuff, all hand typeset, some typewriter pages, hand-drawn schematics.

Yes, this is all probably very inefficient. I have the WiFi oil gauge I've been using for 15 months, and in the past 12 months my oil usage is as follows:

House is 2000 sqft without the attic, and another 800 when that is habitable.
- 1643 gallons - $5600
- 4.5 gallons a day, but june to october its about 1.5 gallons a day, and then a ramp from that to a peak of 10-12 gallons a day through the coldest months. The 7 months we use heating it seems to be about 6.7 gallons a day.

House had fiberglass blow-in into the stud bays many decades ago, the basement is floor to ceiling foamed over a stacked fieldstone foundation, windows are all modern, attic floor had fiberglass blown into the joists, but I also just did foam on the entire attic roof and walls since I am going to renovate and condition it. There are plenty of things that need improvements, so we'll just keep doing one thing at a time.

I'm way to deep into the sunk cost fallacy of bringing this home forward 130 years to stop now. I think the heat pumps will come first for AC and dehumidifying, and to ease up on the boiler during the winter this coming season, then 2023 plan on how to do a total replacement of the boiler and DHW setup, and keep the radiatiors and oil.

One thing I may have to post about by then is: the difference in chimney needs for oil vs. NG. I would love to decomission and remove that chimney someday if NG can be exhausted out a side vent instead of the chimney.