I'm trying to increase the efficiency of my 1968 Weil-McLain 662 without spending too much and doing as much as I can myself. Two-story, 3300 sq. ft. house on a slab with lots of single-pane glass windows big as 5' x 10' that would cost way too much to replace. I'm in the Philly area. In the winter, I've used over 250 gallons in a month. The boiler feeds two zones of baseboard (circulators on returns, not very well distributed) and boosts an electric domestic storage tank. The burner (branded Weil, older head, might be original 45CU-1) had a 1.50 nozzle which I've replaced with a 1.25. I just cleaned the fire chamber and the soot wasn't too bad.

Here's my questions:

1. Would upgrading to a Beckett AF or something similar help efficiency? Is there much difference between an older rebuilt burner and the newest version?

2. Can I go down to a 1.00 nozzle or even smaller safely (on my old burner or a newer one)?

3. My combustion chamber has a bunch of cracks. They don't make exact replacements any longer. Would a generic Lynn be okay or do I need to do something else (and what), especially if I replace the burner?

4. Would a Tekmar 260 or something similar help much?

5. Would a pre-purge, delayed firing update help? Which set-up?

6. Would upgrading the aquastat help? To which one?

7. Any other suggestions?

Thanks!

 

The most cost effective thing is usually insulation and weatherstripping.

A clean boiler certainly helps since the soot insulates the water from the flue gasses.

I'd work first on tightening up the envelope. Once that is done, you may be able to get a much smaller boiler.

 

I've done what I can to insulate better, without spending tens of thousands, including plastic over the single-pane windows in the winter. I know I can get better efficiency out of the boiler. Can anyone help answer my specific questions?

 

> had a 1.50 nozzle which I've replaced with a 1.25

Just an FYI, if you didn't tune the burner after the nozzle change then the efficiency dropped (a lot). You would be better off with the 1.50 until the burner can be tuned for the different nozzle flow. You can tune it yourself but need some test equipment to do it right.

Either an ODR (I believe the Tekmar 260 provides that), or the Beckett Heat Manager should help.

Other then the above I'm not experienced enough in heating systems for the specific questions.

I do know that flame retention burners like to run with positive draft over the fire. Your current boiler may not be designed for this. The doors, chamber area and such need to be sealed.

Al.

 

The nozzle was adjusted after it was replaced, but not tuned with test equipment. What would I need?

The boiler doesn't have doors, but a bolted front cover. The chamber area looks pretty well sealed. The tub-shaped chamber insert has an open top half and looks like the others I've seen.

 

1-3. I'm not an oil guy, so can't help here.

4. Probably. But remember outdoor reset controls are not a silver bullet. Your heating costs will not be magically cut in half. There is also cost and some added complexity. Without piping to ensure that the boiler is protected from prolonged periods of low return water temperatures, you are constrained to a fairly narrow range of water temperatures. The usable temperature range is pretty decent with oil: IIRC return temps need to be about 110F or above. So for example, if your system has a 20F temp drop from supply to return, the lowest supply temp would be 130F. Not awful, but not great either.

But different installations behave differently, and you may need a thermic or other type of bypass in order to avoid condensation. Radioconnection has an oil-fired set-up with a thermic bypass and a tekmar 260. Maybe he will weigh in here.

A control like the tekmar 260 also benefits hugely from having an indoor sensor (speaking from direct experience having done a heating season without and a heating season with the indoor sensor on my 260). It's pretty simple to add an indoor sensor, however, and they can be had cheap on ebay and elsewhere.

I believe the 260 would be the correct choice if you treat the boost as the DHW connection. Due to the way the 260 is programmed, it is better if that is on a dedicated zone with its own circulator.

Post some pics of the system and we can perhaps tell you what kind of hill you will be climbing if you choose to add an ODR control and/or thermic bypass.

5-6. I don't think changing these would help as much as a true outdoor reset control.

7. Don't mean to beat on the "improve the envelope" drum too much, but.... Over the past several years, I've cut my heat loss by at least 15-20% with a few hundred dollars of insulation and a bit of sweat. Compare that to the 15-20% savings of a grand or so invested in a boiler control and maybe some piping. Insulation and air sealing wins every time. Here are some additional tips.

a) Check with your local utility company to see what incentives or programs they are offering. Try http://dsireusa.org/ for a list of current federal and state incentives.

b) get a couple cans of insulating foam. Get up into the attic and foam all the electrical wire penetrations, any ductwork, etc.

c) get a tube of caulk and bead around all the ceiling junction boxes.

d) get a couple cans of minimally expanding foam. Pull the trim off the windows and foam in the gaps. Do the exterior doors, too.

e) For the big windows, consider cellular shades. Even the "cheapies" (~$70 for the 72" wide ones) at Lowes have good insulating properties, particularly if mounted inside the casing. For more $$, consider insulated cellular shades.

f) add blown-in cellulose or fiberglass in the attic.

g) a good introductory guide for this kind of DIY stuff is at

http://energystar.gov/ia/home_improv...OR_100_dpi.pdf

OK, so I went back and now I see that this is a 40-year old boiler. Lyndon Johnson was President when this was installed. If you are going to be in the house for a long time (>6 years), it is probably worth scoping out a new boiler, and perhaps switching over to gas if it is available in your area. Lots of high-efficiency boiler options in gas. Fewer in oil, but a good one would be the Burnham MPO, or the oil-fired offerings from Buderus and a couple others I'm forgetting (Crown? Peerless?). And depending on electricity prices, going to an indirect water heater would be helpful as well. Good news is that any of these boilers would benefit greatly from a control like the tekmar 260.

 

It could make it worse. The two primary things affecting your boiler's consumption are how well it is tuned and how clean the heat exchanger area is. How was your current burner tuned? Any idea of what your stack temperature is.


Not likely... The first question here is how long are your heating cycles? If you are short cycling then you would try and reduce capacity if possible but if you have long burn cycles then you will just messing things up. The combustion gases fill the flue passages. Put less gases in there and you could get less heat exchange taking place and actually reduce your efficiency (burn oil less quickly but for longer and not get as much heat out of it). How long are your on off cycles at normal and really cold temperatures?


ODR will help to some degree but it will shorten your cycles in the milder seasons. It achieves more gains in comfort than efficiency.

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Setback t-stats if you don't already have them.

Exterior storms would probably help greatly and could be DIY.


You might want to go to the SlantFin web site and download a copy of their free heat loss tool. Enter the specs for your house. Then you can what size boiler/nozzle would be optimal and you can also model things like changing infiltration / leaks and what kind of return you get on caulking and foam cans. You could see what another 6" of insulation in the attic would do. Just trying to help... 250 gallons a month hurts, but in terms of getting that down, many of your suggestions won't change things much. At the end of the day the boiler's job is to replace the heat that leaked.

 

Just a point of information. A delta T in a hydronic system changes with water temp. The 20º delta tee is at design water temps. If design water temperature is not know the default to 180º is normally used for standard radiation (high temp systems). As we drop water temperature the delta T drops. With a system operating at 130º the delta T could be as low as 8º, dependent on the variables. What determines the amount of condensate the most is the type of fuel. From most to least condensate produced is natural gas LP than fuel oil. For every 100k of natural gas burned equals 1 gallon of condensate, 12% less for LP and 40% less for fuel oil. Also the temperature the unit starts condensing changes with different fuels.

 

The tools for setting up the burner/boiler:

Smoke pump (Baccarrach True Spot)
Draft gauge (Dwyer 460)
CO2 meter
Thermometer (for stack temp, needs to go to 800 F or so)
Pressure/vacuum gauge (for checking pump pressure 0 - 150 psi, for checking pump vacuum 0 - 30")

When you changed the nozzle to 1.25 from 1.50 there is now too much air for the amount of fuel. This excess air carries the heat out of the boiler and up the chimney. Using the smoke pump & CO2 meter the air to fuel ratio (AFR) can be checked and then adjusted.

The stack temperature & CO2 % tell what the efficiency is. With the stack temperature & draft readings there are other adjustments that may need to be made.

When I started out I googled and read a LOT of information about boilers & burners before and as I dove in.

Al.

 

A lot of information coming in, which I really appreciate. Here's some more details that may help:
The cycles seem short. I had a 1.00 nozzle in for a brief time and the cycles were much longer. I will time them tonight. The water temp gets up to about 170-180 degrees at 25 lbs. pressure. Comfort is important.

My windows have a lot of angled tops, so shades and storms are pretty tough. (I'll post a photo when I can figure out how to get that permission on the forum.) There's no attic-just high ceilings upstairs. The peaked roof is a series of SIPS (the main part was originally a 1956 tek-built house), but with minimal insulation. It would be hard to blow in insulation because of all the compartments. At least there's no penetrations for electric or ducting in it. All the small, opening windows have been covered with plastic. The big ones don't open. I don't expect to stay longer than five years, so a new boiler is out, and there's no gas service anywhere near.

I'll post some boiler room shots tonight.

 

Photobucket is probably the place most photos here are hosted... then you can provide the link.

 

It's cycling pretty quickly--about 10-12 minutes on, 3-5 off, 10-12 on again.

Here's the windows and this doesn't include the biggest ones. This is why replacing them all would cost so much.



The boiler room is under a stairway and it's pretty tight. The water heater has its own circulator. It's almost impossible to get to the flue.

 

Why is the draft regulator cemented shut ?

There should be a pipe on the pressure relief valve down to the floor.

What's with all the rust around the tankless coil ? Leaking ?

 

I don't know why the regulator is shut, and none of the techs who have serviced the unit in the fours years since I bought the house have ever said anything about it. Same for the pressure relief valve. That's why I decided to start doing this myself with the help of this forum. The amount of rust hasn't changed over that time.

 

I guess none of them have ever put a draft gauge on it then. But I'm not surprised ...

 

Paul, nice place. If only it would have been built at a time when energy didn't cost so little.

Check Craigslist for 30 meter acrylic domes - don't forget to vent the boiler outside of it...

Maybe just consider a new modern boiler... the fuel saving would carry the interest on it and the difference in selling price would probably cover the cost. The current boiler really looks like it could affect the value. A new boiler will still look new in 5 years. Just food for thought.

 

That boiler owes no one anything.

I agree with Who (except on the acrylic dome!). A buyer's home inspector would definitely say the present boiler is grounds for negotiation, and you'll be there long enough to recoup some costs from the upgrade.

If gas is available, stick a Munchkin in there.

If oil, find a small one.

Do a good heat loss calc first.

 

I did the Slant Fin program and got a heat loss of 149,000 BTU/HR. I would love to buy a new boiler, but I don't have the cash to even carry the interest right now. (Although maybe I can find a used bargain on eBay/craigslist.) So, what can I do right now with what I have is still my problem. Sounds like I should open up the damper, test what I can (although the CO2 meters are out of my range), and possibly get a Tekmar 260. Should I replace the combustion chamber tub? Is replacing the burner not worth it, even if I get a rebuilt one at a good price? Any other suggestions or advice on these would be much appreciated.

 

Suggestions for old oil boilers are out of my range. But I would say take a good look at the total cost of what you'd do and compare that to what a replacement might cost. Could be you get halfway there just for the tuneup and related parts. The 260 would be the last thing on my list. But it would be useful for a new boiler if you did get it now.

 

I am by no means technically versed as Xiphias, Who or NJ Trooper, who by the way changes avatars on a daily basis

I had done what I could to block the holes in my home, but setting the thermastat at 70 the house was still cold.
I needed a service call on the boiler, that was 30+ years old, my service man said he could fix it and he said it was only about 40%-50% efficient. He also indicated it will nickel and dime me to death over the next few years. Parts were hard to come by and anything to be added would have to be modified to fit ie:$$$.

So I bought a new Buderus that is 80% efficient, which is quite a jump from 40-50%!
In my first year of oil use I used 875 gallons vs 1500 gallons on the old system, if my math is right thats about 40% savings in fuel and should do better this year.
I set the thermastat now at 67 and am quite comfortable.
My hot water is heated by the boiler also. The new installation earned me about $450 in tax credits on my tax return all good stuff.

So you have a choice to continue to throw money at it now or invest in a new unit and save money later...

Mark_ms

 

Looks like I may defer to the forum's accumulated wisdom. I may have found a Peerless WBV-04-150 with a Beckett burner, but no tankless coil, that was installed two years ago, used for only two heating seasons, and replaced by a forced air system when the home's buyer did a complete renovation. It's only a couple of miles from my house and would cost about a grand w/ controls. I would have a qualified tech (who would design the layout and help w/ or do the installation) inspect it. Does that seem like a good option?

 

Paul, no disrespect to your proposed technician, but if you want, you could probably get a pretty good idea of how the boiler should be piped and controlled from the folks here. When a technician is doing a job, there #1 thing is to do it well enough that they don't get called back. The other thing is to make sure they are inexpensive enough to actually get the job and you feel good about the value. With more thought and a bit more in the way of fittings, and install job can move from a 6 or 7 to an 8, 9 or 10.

With a well thought out design, the technician will know exactly what you want, need and more important expect. That allows them to properly bid on it (time is their big factor and the materials will then be a given - not what he can find in his truck while installing it).

Food for thought.

 

I take it the -150 is the 1.5 nozzle. If you can use a 1.25 or even a 0.95 nozzle, that would get it firing at closer to your heat loss (and note that your 149k heat loss is probably overstated by 30% -- most Manual J calcs seem to be that way). I'd use the 0.95 nozzle.

Sure, here on the other side of the internet, a young boiler for a good price might be well worth it. The key will be getting it out of the old install and into your place without cracking a section, etc. You won't have any warranty recourse, I suspect, and the installer or you may or may not cover accidental damage or breakage. If the boiler is already removed from the old house, then it should be inspected and maybe even pressure tested to make sure the demo guys didn't break something.

In your tight boiler space, layout will be key. Bunch of us here, as Who says, are real geeks when it comes to layouts and would be happy to lend a virtual hand in diagramming and placing components, suggesting fittings for ease of tight space maintenance, etc.

 

It's been disconnected, but apparently not moved from the basement. I'll be sure to get enough help to move it safely, but I know it will be at my risk.

I'm willing to try doing most of it myself. I worked as a plumber for four years, many years ago. I never did boilers, just installed water, gas, steam radiators, and sprinklers, so my heating engineering knowledge is zip, but I still have almost all of my tools and what's left of my common sense.

My layout will be very tight. Your offer of help is much appreciated. The heating guy I will use is happy to work by the hour, but I really do need to keep the cost down.

 

Can anyone help me get parts for this burner please email me at: [ed- sorry, emails not allowed... PM if you want]

Or can someone guide me in a replacement oil burner for this Burner.

Weil Mclain Flame retention Model 45CU-1