Some Near Boiler Questions After Dan's Video Last Week...

cubicacres

After watching Dan's near boiler piping video last week, it reminded me of a few questions we had about our single-pipe steam system for our 5 unit apartment building in Milwaukee, WI.

I was going through old photos of the Weil McLain EGH85 steam boiler we replaced in fall 2015 with our new WM EG75, and have some of the old EGH85 boiler photos attatched for comments. Our observations & questions about the old boiler setup are:

1. We thought the intake for combustion air in the boiler room's window was too small for the old boiler from CFM/BTU calculations by 30-50%, so we increased the size with our new boiler install & added a 50% extra margin of safety.
2. The old boiler was directly on the floor of the boiler room (our new one has some bricks under it), and had a lot of rust on the bottom of the jacket/was rusty inside when we removed it per the photos.

Would the under-supply of intake combustion air and/or running for a shorter period of time if oversized cause the rust buildup we saw on the old EGH85 boiler over its 20-25 year life in there? We had just replaced the water supply piping in the 3rd photo a few weeks before these pictures were taken, since it had been leaking & was all rusty/corroded. It almost seemed like there were water leaks or flooding in the boiler room to cause that much rust on the boiler over time, compared to how our 5 year old boiler is looking so far. Any thoughts about how all that rust got there, or is this pretty typical for an old boiler?

Hap_Hazzard

Atmospheric boilers usually don't need a dedicated air inlet, unless the boiler room is air-tight. If too little air is getting in, it would prevent flue gases from being exhausted, and the room would be full of carbon dioxide, carbon monoxide and water vapor. Water vapor and carbon dioxide would tend to promote corrosion, but it would affect all the metal in the boiler room, and the CO and lack of oxygen would probably kill you.

Theoretically, an air intake wouldn't need to be as big as the flue, because cold air is denser than hot air.

Rust generally forms on boiler and piping in residential basements because they tend to be very humid in the summer. Maybe that's all that going on here? ¯\_(ツ)_/¯

Steamhead

@cubicacres , good to hear from you!

With those EG/EGH series boilers, the section gaskets start leaking along the bottom and that's what causes the rust. We just replaced an older EGH-85 with an SGO-9/Carlin 201Gas because of this same issue.

cubicacres

Glad to be Back, Steamhead Thanks-it is humid down there, with condensation forming on the cold water copper pipes in summer. We did notice the CO2 detector in the boiler room was ok with the CO2 levels over time, and our new boiler riser/header/equalizer pipes rusted from black to brown over the first summer as well, so maybe that's where the rust came from along with the sections leaking.

Bonus question: This picture was our old boiler wall control setup before we installed the new one with a Tekmar contoller & outside warm-weather shut down. Do you know what this old set of controls did & how it might have compared with our new Tekmar & WWSD setup>?

ethicalpaul

What material could the boiler sit on that would prevent/reduce that rust area at the floor? Clearly resting on the floor concrete isn't great, especially it if can be damp.

Blocks might be a little better, but is there something that can be put on the blocks to really keep the rust at bay?

ChrisJ

ethicalpaul said:

What material could the boiler sit on that would prevent/reduce that rust area at the floor? Clearly resting on the floor concrete isn't great, especially it if can be damp.

Blocks might be a little better, but is there something that can be put on the blocks to really keep the rust at bay?

Sure,
A Stainless steel boiler.

Jamie Hall

There are basically two problems -- but they are related. First, concrete, and concrete blocks, have relatively high heat capacity A fancy way of saying that they cool and warm slowly. This is significant because basement humidity is usually high, and if the concrete is cool... presto, soggy and rust.

The solution is to separate the boiler from the concrete as much as possible. Even a set of very short feet under it would do the job -- but that often isn't feasible. There is, however, a product called AirKrete (and there are other similar products) which, in combination with a plastic sheet vapour barrier between it and the underlying concrete, will do the job very nicely -- and has enough strength to hold the boiler up.

JUGHNE

Just about everything I put in a basement is set up on 3 1/2" solid concrete blocks. (4 x 8 x 16 solid CMU blocks).
Even AC condensing units that are already on a poured pad might get the blocks. Keeps the weed eater at bay.

This gets equipment up at least above a 3" floor flooding.
Also that little height raise makes servicing a little easier.

Yes, it is concrete sitting on concrete. But the basement floor is in direct contact with often damp soil. The blocks have the other 3 to 5 sides open to air for drying out.

One little discussed possible issue is with a boiler that does not have corner legs or a pan under the boiler burners.
If blocks or legs are added under just the corners of the boiler then is the original combustion air flow affected......coming from below rather than the front of the burner assembly???

I recall one discussion of this and the installer said they add a solid pan under the boiler to account for this situation.

ChrisJ

JUGHNE said:

Just about everything I put in a basement is set up on 3 1/2" solid concrete blocks. (4 x 8 x 16 solid CMU blocks).
Even AC condensing units that are already on a poured pad might get the blocks. Keeps the weed eater at bay.

This gets equipment up at least above a 3" floor flooding.
Also that little height raise makes servicing a little easier.

Yes, it is concrete sitting on concrete. But the basement floor is in direct contact with often damp soil. The blocks have the other 3 to 5 sides open to air for drying out.

One little discussed possible issue is with a boiler that does not have corner legs or a pan under the boiler burners.
If blocks or legs are added under just the corners of the boiler then is the original combustion air flow affected......coming from below rather than the front of the burner assembly???

I recall one discussion of this and the installer said they add a solid pan under the boiler to account for this situation.

I've asked this and was told it's not a concern.
That confuses me because I thought WM insists the front and back panels are installed on the block or it will effect combustion air. If that's the case, how can a big gaping hole across the whole bottom not?

I don't know.
I plopped mine right down on the partial concrete floor because I was concerned about height.

KC_Jones

If you are condensing on the copper pipes, I would be looking into de-humidification for sure. I know in my house, with a workshop in the basement, the moisture would cause corrosion on any metal in weeks, not months or years, weeks.

On a positive note, many of my tools have an incredible patina on them.

ethicalpaul

Jamie Hall said:

There are basically two problems -- but they are related. First, concrete, and concrete blocks, have relatively high heat capacity A fancy way of saying that they cool and warm slowly. This is significant because basement humidity is usually high, and if the concrete is cool... presto, soggy and rust.

The solution is to separate the boiler from the concrete as much as possible. Even a set of very short feet under it would do the job -- but that often isn't feasible. There is, however, a product called AirKrete (and there are other similar products) which, in combination with a plastic sheet vapour barrier between it and the underlying concrete, will do the job very nicely -- and has enough strength to hold the boiler up.

thanks everyone, but especially @Jamie Hall whose response above really made a lot of sense to me. I'm going to look at that and similar products I might find.

I have enough "A" height to be able to put on blocks/feet, thankfully.

Regarding the airflow @ChrisJ I think it could be a concern. But that concern should be mitigated by putting the boiler on a flat layer of blocks (or whatever) that doesn't allow much if any "extra" flow of chimney effect from the bottom. And sorry for the hijack.

JUGHNE

Another reason for blocks, in 1995 our boiler 100K WM GV Gold boiler showed up, my wife looked at it and said that will never heat our house (+4000' finished plus DHW).
After putting it up on the 4" blocks so it gained some height, she felt better about it's capability.
Years later upgrading to a KBN80, I put a double layer of 4" blocks under it for dramatic effect......BTW, she never seen me carrying it downstairs by myself.

But sitting on a bucket with the 8" blocks makes maintenance a lot easier.

Another story; was the EC on a fair sized remodel/addition of a community center. The MC was a screw up from the beginning.
The GC was getting pretty upset with MC, liens on the job etc.
At the final walk thru, the owner pointed out that all 10 FAF's were sitting on a wet floor. The GC and architect pointed out that there were no "equipment housekeeping pads (4" concrete separate pads) under each unit, as stated in the spec book. They inquired to me what that was worth knowing that I was also HVAC installer. I said I could add a pad after the fact for about $1000.00 each.......10 large NG FAF with large duct work and AC lines.

The GC said "fine then" and cut a check for $10,000.00 to the owner out of the MC's bid/hide. The architect approved it on the spot and now we have an excellent sound system in the comm center.
(never did get pads under equipment.....the worst basement floor stayed dry ever since.)

ethicalpaul

Great stories @JUGHNE ! I especially love "boiler sizing via wife's quick glance"!!

BobC

Years ago I wanted to reduce the humidity in my basement, I tried a dehumidifier but they use a fair amount of electricity and with today's power costs (22 cents per KWH here) who wants that.

This is a 100 year old house, one of the first with a poured foundation. I have wood 3 pane hinged cellar windows. I took a pane out of one window and bought a piece of lexan cut to fit. I put a 4" hole in that pane and mounted a 4" muffin fan it it that is rated at 100cfm.

I plug that fan in in may and unplug it in October, I think it uses about 15watts and will use a KWH every 3 days. This is a small two story house and that fan will exhaust all the air in the basement every 47 minutes. The basement isn't humid any more and my electric bill isn't onerous either.

When I unplug the fan I mount a shield that blocks that fan to keep out the cold winter air and any mice looking for a nice warm cellar.

Bob

ChrisJ

BobC said:

Years ago I wanted to reduce the humidity in my basement, I tried a dehumidifier but they use a fair amount of electricity and with today's power costs (22 cents per KWH here) who wants that.

This is a 100 year old house, one of the first with a poured foundation. I have wood 3 pane hinged cellar windows. I took a pane out of one window and bought a piece of lexan cut to fit. I put a 4" hole in that pane and mounted a 4" muffin fan it it that is rated at 100cfm.

I plug that fan in in may and unplug it in October, I think it uses about 15watts and will use a KWH every 3 days. This is a small two story house and that fan will exhaust all the air in the basement every 47 minutes. The basement isn't humid any more and my electric bill isn't onerous either.

When I unplug the fan I mount a shield that blocks that fan to keep out the cold winter air and any mice looking for a nice warm cellar.

Bob

I've never done this because of how humid it gets in our area, especially at night. I suppose it depends on where you are.

I decided to spend the money on a dehumidifier because it was far cheaper than renting a storage unit for tools etc and the side benefit was it helps the house. Although, the house did survive something like 140 years with an extremely humid basement and crawlspaces. The first year we lived there I measured something like 85% RH down there. I keep it in the low 40's with the dehumidifier.

PMJ

What was wrong with the standing pilot again? I run mine all summer. Easily keeps the whole unit above the dew point. My boiler sits right on the concrete floor. No rust at 64 years. Pilot has never been out.

Oh right I forgot, it wastes too much gas. Hmm.

cubicacres

We have 4 cinder blocks under the boiler, one on each corner. WMC tech mentioned their lab tests used a solid layer of bricks, so maybe some chimney effect reducing our boiler efficiency. Not sure how much & if it's worth filling in the space with more cinder blocks to make a solid platform under the boiler or not. I was a little concerned if one moves or slips, then could an edge of the boiler lean down out of place/split a section apart?

Also, was that old wall photo above an outdoor reset/warm weather shut down & wall thermostat we removed with the old boiler? We never adjusted it since the boiler was replaced shortly after we bought the building & before we began learning about steam boilers. We did see a wire going outside to the NE corner of the building in the same area our new WWSD is, but it was cut, so never made it outside when we operated the old boiler.

Steamhead

cubicacres said:

We have 4 cinder blocks under the boiler, one on each corner. WMC tech mentioned their lab tests used a solid layer of bricks, so maybe some chimney effect reducing our boiler efficiency. Not sure how much & if it's worth filling in the space with more cinder blocks to make a solid platform under the boiler or not. I was a little concerned if one moves or slips, then could an edge of the boiler lean down out of place/split a section apart?

Blocks are cheap- can't hurt to try.

cubicacres said:

Also, was that old wall photo above an outdoor reset/warm weather shut down & wall thermostat we removed with the old boiler? We never adjusted it since the boiler was replaced shortly after we bought the building & before we began learning about steam boilers. We did see a wire going outside to the NE corner of the building in the same area our new WWSD is, but it was cut, so never made it outside when we operated the old boiler.

I think you're right. There were all kinds of outdoor controls back in the day. Nowadays Tekmar and Heat-Timer pretty much own the market, at least around here.

cubicacres

Thanks!
Now a few questions about our new WMC EG75 boiler setup (first picture is shortly after install & before our insulation work/rust patina appeared):





1. Does it look like we have the header expansion offset ok per Dan's reccomendation in his near-boiler video? We hope header expansion when running would rotate the riser elbows or another joint a bit rather than force the boiler sections apart.
2. We were talked out of adding a king valve on initial installation & have been blowing down the boiler using the 2 lower ports on each side with regular water pressure. How important/worthwhile would it be to try and add a King valve to isolate the boiler for higher pressure to force out more sludge ocassionally with higher PSI pressure? Would this add several years to the expected life/better ongoing operation to more than offset the king valve installation cost?
3. We do use steammaster tablets (1 each time in the fall start-up/mid-winter/upon spring shut-down when raising the water level & heating it to 150F for a few minutes). Does this help with our lack of a king valve/new water use from undiscovered leaks? We noticed some months use 2-3 gallons of fresh water, some up to 20 or so, but it's harder for us to ask tennants to inspect their radiators when it's running to find all the leaks. We did go around replacing about 8-10 radiator supply valves & 5-6 other supply valve packing nuts with graphite strings a few years ago. Would the steammaster tablets let us relax about using more fresh water? We were also curious if some boilers don't require any chemcials, depending on the local water composition. If we should get our water tested, we could do that as well.
4. Is the equalizer reduced in size too fast, or look ok for our setup? It also has the angled-down elbow vs. a 90 degree turn-not sure if that matters.
5. We'll also try and add a pigtail to each gauge & pressuretroll at some point.
6. Our main has the single 4-5 inch? rise from the header where a king valve could be added. It then goes outside the boiler room to a split bull-headed T, I think (3-4 inch each direction?). The right path starts our short loop back to the boiler, the left path is the medium line which has our 3rd longer loop start about 15 feet after this T with an angled smaller 2.5 inch? pipe to start the long loop (we know the longer loop has smaller steam input, but that's another issue we've been talking with steamhead about) . What would the cost/benefits be of adding another rise-pipe coming our of the header to avoid the bull-head T?

rick in Alaska

I took Tim McElwain’s gas class and I vaguely remember him talking about raised atmospheric boilers that were not on a solid foundation. I don’t remember the exact reasoning, but with a non solid base, it messes up the intake air pattern and can cause issues.
Maybe Tim will see this and chime in.
Rick

Hap_Hazzard

Maybe if you mention @Tim McElwain in your post.

ethicalpaul

1. My rough calculation of your header expansion is like 1/32" of an inch from 70 degrees to 200 degrees, I think you have nothing to worry about. But I'm strictly an amateur.

Based on how my near boiling pipe joints are frozen solid, requiring a massive cheater just to move them at all, I think it's a big non-issue for all but large commercial installations.

Finally you have pretty long lengths of pipe in your near-boiler piping and they will bend if needed.

4. I can't see the size of your equalizer, but you could look in your boiler's manual, it will specify the minimum spec'd size. But with the height and size of your steam supply risers and the fact that there are two of them, I honestly think there's only going to be a trickle of water ever coming down it (and probably less than a trickle--more like a wet coating on the pipe interior).

5. I don't think you have to. They all are connected via the one pigtail, right? It will protect all of them I think. (edit: I'm wrong, corrected by Steamhead in the next message, thanks!)

6. Personally, I think you will have no benefit from reconfiguring this bullhead T. Your near boiler piping is in really excellent shape and I'd bet a lot of money there's no water getting up to your main. And if it's insulated there's precious little water coming down it (even if not insulated there would be precious little). I can't see the benefit of doing anything to it. These statements assume you have a. parallel flow and your main is at its highest point near your boiler and slopes down appropriately as it runs around to other places, terminating in one or more wet returns.

Steamhead

ethicalpaul said:

5. I don't think you have to. They all are connected via the one pigtail, right? It will protect all of them I think.

Actually, each Pressure control needs its own pigtail. The reason is, if one pigtail gets plugged, it won't cut both controls off from the boiler.

Not sure what Code is used in Milwaukee, but in Baltimore, a boiler of that size not only needs two pressure controls and two low-water cutoffs, but the secondary one of each (tripping at a higher pressure or lower water level) must be of the manual-reset type. Even if it weren't required, it would be a very good idea to go that way.

cubicacres

Thanks-adding some bricks for a solid base under the boiler seems easy enough.
Good to know header expansion worries may not be so critical for our setup & the length of pipe can help with that.
I think our equalizer was sized ok per the research we did, but I think the pipe reduces in size a few inches after the elbow, so I wasn't sure if that could be a problem since other photos of boilers I saw had the same pipe size further down for another foot or two.
Also never noticed problems with the bullhead T (I think it is parallel flow) with the Bullhead area highest to the ceiling with a gradual slope down back to the returns over the 3 main loops we have.

Any thoughts about adding a king value after our initial install to help remove sludge? We do skim the boiler at least once a heating season (From around Oct-May here in Milwaukee, WI), blow it down from both sides 2-3 times a season, and use 1-2 tablets of steammaster per season.

And using chemicals like steammaster tablets vs. no chemicals at all? We thought since we didn't find all the leaks a few years back, the tablets would take the urgency out of letting a few more gallons of new city water in per week. Ideally we'd stop all leaks each season we detect the higher water use from the meter, but they seem to get better for a few months, then worse season to season/month to month for us.

Jamie Hall

Well... steamaster won't hurt, so long as you don't use too much of it. What will really help is finding the leaks. Bad radiator valve packing. Vents not sealing properly. Even a tiny drip from a threaded joint somewhere on a steam line -- or a return. But a few gallons per week is just not good.

cubicacres

ok, we can check them again. Any thoughts on monitoring all those potential leak spots during a few minutes of boiler steam time if they're in separate apartment units (3 main loops serving 5 apartment units, 3-5 radiators each unit=about 20-25 radiators+ lines)? We want to stop the leaks, but also don't want to bother the tenants to check everything. We thought about doing it all on a day we run the tekmar max heat setting for a while, but then it might create new leaks under cut-off psi of 2-3 on our pressuretroll if it usually doesn't run that strong under most circumstances? And if we do find & fix the leaks, someone could bump a radiator vent next week/a vent fails and we're back to the hunt again as we monitor the water feeder? We were hoping when we got the water back down to 2 gallons/month a few years ago we were all set