Time to Tear Into Things - Need Advice

drewbert41

I have a relatively new Lennox Dunkirk boiler connected to the existing pipes from 1913. The pipes below the water line developed multiple pinhole leaks this season and it is time to rip it all out. It has an extremely low header and I have wet steam and water hammer. There are two mains, but it has only one pipe leading to it and splits later.

If I turn the water off, drain the boiler, and cut out the old pipes do I need to know anything going into it? I plan to do it this off-season with a plumber buddy of mine. We both have young kids and this will be a multi-weekend \ month project. Do I need to worry about the inside rusting out or anything? Anything to be aware of when filling up, turning back on, testing?

As far as design goes I have the piping diagram for my boiler that was provided to me by someone on here. Everything needs raised to the 24" mark and I need to run the two mains off the side of the header from what I am reading. Do I have the right idea in my drawing with the red and blue designating the two mains and how I should run them? Also, someone said on here that my Hartford loop is wrong. I believe I should also be installing blow-down valves on the mains correct?. I think I also need to move my vents back from the ends of the returns a little. Any tips appreciated.

Also, where should I get my pipe, supply house? I need to find the blue pipe tape as well?

drewbert41

Should I reuse some of the large piping above the water line? I wan't to replace everything below the water line for sure.

dopey27177

The drawing shown is perfect and should be followed if you are willing to do the extra work.
The boiler header looks too low in relation to the boiler water line.
I prefer wet returns, if you are willing to install wet returns do them in type l copper using 95/5 solder.
Follow the drawing even if you decide to use one riser off the steam header.

At the Hartford loop use a close by extra heavy nipple.
Very important insulate the steam main. Saves energy and will prevent excessive condensation which causes banging.

Jake

drewbert41

I have a bunch of insulation, but have been holding off. The drawing has everything on the right of the boiler and mine will be on the left.

nicholas bonham-carter

Check the diameter of the side outlet nipples from the boiler to make sure they are the correct size, or they will have to be removed, and enlarged, (check the installation manual for minimum sizes).
The pipes/fittings are new enough so that they can be reused, if you can find someone to thread them for you. The local plumbing supply house may cut and thread new nipples bought from them, but maybe not the old ones.
A drop header will make it easier to fit everything together as you go. Don’t apply the pipe dope with a trowel!
The header should be bigger than the two outlets, if possible.
Copper below the waterline will be best for the long run.—NBC

Steamhead

On that boiler, I would make the horizontal portion of the header 3-inch. Those Dunkirks are notorious for wet steam, and the larger header would help dry it out. the two 2-1/2" risers from the boiler to the header are fine, but they need to be 24" high per the diagram. This also helps dry out the steam.

Then pipe the steam mains individually as you propose, and the system will work much better. Don't forget to upgrade your main vents if you haven't already.

ethicalpaul

You're going to love this project and it won't take very long if you have a plumber buddy. Get a 24" and a 36" pipe wrench from harbor freight if you don't have them already.

supplyhouse.com is your friend. Blue monster tape is fine. Try to do all the near boiler piping with your existing pipe and fittings and then just order any nipples/fittings you need from supplyhouse.

In my DIY experience, the trickiest part is the connection from the header to the equalizer. The rest is very straightforward with reasonable room for error. Getting a downward pitch on the header is an art form, but personally I don't worry if it's level.

You can take up a lot of slack with "just one more turn" of any given pipe or fitting. If you need even one or two more turns after that, try it with pipe dope only instead of tape.

https://forum.heatinghelp.com/discussion/181981/new-boiler-install-edit-passed-inspection

mattmia2

does that enormous boiler match the edr? if it is like double the size it should be, might think about going with the right size of you are going to go through all the work of repiping it.

drewbert41

nicholas bonham-carter said:

Check the diameter of the side outlet nipples from the boiler to make sure they are the correct size, or they will have to be removed, and enlarged, (check the installation manual for minimum sizes).
The pipes/fittings are new enough so that they can be reused, if you can find someone to thread them for you. The local plumbing supply house may cut and thread new nipples bought from them, but maybe not the old ones.
A drop header will make it easier to fit everything together as you go. Don’t apply the pipe dope with a trowel!
The header should be bigger than the two outlets, if possible.
Copper below the waterline will be best for the long run.—NBC

Thanks, Copper sounds great.

drewbert41

ethicalpaul said:

You're going to love this project and it won't take very long if you have a plumber buddy. Get a 24" and a 36" pipe wrench from harbor freight if you don't have them already.

supplyhouse.com is your friend. Blue monster tape is fine. Try to do all the near boiler piping with your existing pipe and fittings and then just order any nipples/fittings you need from supplyhouse.

In my DIY experience, the trickiest part is the connection from the header to the equalizer. The rest is very straightforward with reasonable room for error. Getting a downward pitch on the header is an art form, but personally I don't worry if it's level.

You can take up a lot of slack with "just one more turn" of any given pipe or fitting. If you need even one or two more turns after that, try it with pipe dope only instead of tape.

https://forum.heatinghelp.com/discussion/181981/new-boiler-install-edit-passed-inspection

Thanks I appreciate it. Any advice for how long it can be apart\ rust \ tips for success when firing it back up?

drewbert41

mattmia2 said:

does that enormous boiler match the edr? if it is like double the size it should be, might think about going with the right size of you are going to go through all the work of repiping it.

I am not sure. It is only 6 or 7 years old maybe. We have 4,000 sqft and lots of pipe.

ethicalpaul

drewbert41 said:

Thanks I appreciate it. Any advice for how long it can be apart\ rust \ tips for success when firing it back up?

It can be apart for years Don't worry about rust, it will happen where it happens.

For firing it up, make sure your main venting is in order, have a low pressure gauge like 0-3 psi, have your pressuretrol set at .5 cut in (for the common additive type) and tell the thermostat you want it 3 degrees warmer than the current temperature. This will give you a nice long fire cycle to watch.

When you start, have the water below the level of your LWCO to make sure it "sees" the low water condition and refuses to start up your boiler. Then add makeup water to the normal water level to see if the LWCO then allows the boiler to fire.

If it were me, I'd also put Maid o' mist #4 on all the first floor radiators, and #5 on all the second floor radiators as a starting point. ($9 at suppyhouse). I'm assuming you have 1 pipe steam.

Watch the pressure as it starts to boil. You should see it go up just slightly. You should hear or feel air escaping from the main vent during this time. The pressure should be like 1/4 psi or less. Hopefully no leaks at this point! I see your main vent is all the way back at the boiler. This is OK but I like it better when it's just past the last radiator supply pipe.

Follow the steam (by gingerly touching) as it heats up your main(s). Follow it to the main vent(s). See that the main vent(s) close against steam and don't leak after they get "steam hot". Look at the pressure as this happens. You should see it go up slightly as the main vent(s) close and the air starts to get pushed exclusively out of the radiator vents. Look and listen for any leaks in your new connections. If the pressure rises during this phase beyond like 1/2 psi your boiler is likely oversized. It's not the end of the world.

Now start to run around to the radiators. This phase is long so you don't have to run too fast. See if the radiator vents are letting air out. It should be very slow venting. Hopefully all radiators should start to see steam at their supply valve at around the same time. The radiators will start to heat up from the supply side.

Periodically run back downstairs (or have your helper on the phone) to see what the pressure is. Hopefully it will remain nice and low during this phase, below 1/2 psi (mine is at like 1/50 psi -- 1/2" of water column, but many boilers are oversized so they run higher psi while they are filling the radiators).

If the pressure does start to build above 1psi now is your chance to really listen for leaks (you may not see them on the near boiler piping because there's a lot of heat and the steam may just evaporate off without condensing on the piping, but you might find a drip). Depending on the size of your boiler, pressure might rise up to the cutout point. Keep track of how long the cycles are if it does this to report back.

Check the radiators again to see if they are all getting hot. See the thermostat get satisfied and see the boiler turn off. That's how I do it.

drewbert41

ethicalpaul said:

drewbert41 said:

Thanks I appreciate it. Any advice for how long it can be apart\ rust \ tips for success when firing it back up?

It can be apart for years Don't worry about rust, it will happen where it happens.

For firing it up, make sure your main venting is in order, have a low pressure gauge like 0-3 psi, have your pressuretrol set at .5 cut in (for the common additive type) and tell the thermostat you want it 3 degrees warmer than the current temperature. This will give you a nice long fire cycle to watch.

When you start, have the water below the level of your LWCO to make sure it "sees" the low water condition and refuses to start up your boiler. Then add makeup water to the normal water level to see if the LWCO then allows the boiler to fire.

If it were me, I'd also put Maid o' mist #4 on all the first floor radiators, and #5 on all the second floor radiators as a starting point. ($9 at suppyhouse). I'm assuming you have 1 pipe steam.

Watch the pressure as it starts to boil. You should see it go up just slightly. You should hear or feel air escaping from the main vent during this time. The pressure should be like 1/4 psi or less. Hopefully no leaks at this point! I see your main vent is all the way back at the boiler. This is OK but I like it better when it's just past the last radiator supply pipe.

Follow the steam (by gingerly touching) as it heats up your main(s). Follow it to the main vent(s). See that the main vent(s) close against steam and don't leak after they get "steam hot". Look at the pressure as this happens. You should see it go up slightly as the main vent(s) close and the air starts to get pushed exclusively out of the radiator vents. Look and listen for any leaks in your new connections. If the pressure rises during this phase beyond like 1/2 psi your boiler is likely oversized. It's not the end of the world.

Now start to run around to the radiators. This phase is long so you don't have to run too fast. See if the radiator vents are letting air out. It should be very slow venting. Hopefully all radiators should start to see steam at their supply valve at around the same time. The radiators will start to heat up from the supply side.

Periodically run back downstairs (or have your helper on the phone) to see what the pressure is. Hopefully it will remain nice and low during this phase, below 1/2 psi (mine is at like 1/50 psi -- 1/2" of water column, but many boilers are oversized so they run higher psi while they are filling the radiators).

If the pressure does start to build above 1psi now is your chance to really listen for leaks (you may not see them on the near boiler piping because there's a lot of heat and the steam may just evaporate off without condensing on the piping, but you might find a drip). Depending on the size of your boiler, pressure might rise up to the cutout point. Keep track of how long the cycles are if it does this to report back.

Check the radiators again to see if they are all getting hot. See the thermostat get satisfied and see the boiler turn off. That's how I do it.

Awesome tips thank you. I have never had any pressure issues. Always stays super low. Proper near boiler piping should help that even more I would think. I like what you said about the main vents and will have to look into that. My vents at the radiators are all ok. I assume I will have to skim quite a bit afterwards as I am sure I will knock a bunch of crap loose in the pipes when I cut them.

Will adding a bigger header and changing how the mains are run require me to mess with the pressure or can I leave it how it is?

ethicalpaul

Knocking things loose won't require skimming. That stuff will find the lowest point. What will require skimming is the oil from your new pipe and fittings. After it's been running for a few days to a week, give it a skim.

A different sized header and changes to the mains layout won't require you to change anything about your pressure. Congratulations on your low pressure, it's a nice condition to have.

drewbert41

Does the lowest part of the drop header need to be 24" above the waterline? I am trying to do something like this picture and I am looking to buy 24" nipples and drop from there. Do I need to use a union and go higher? I have room to go higher and still drop under my flue pipe.

EBEBRATT-Ed

@drewbert41

The lower part of the drop header only needs to be above the water line but I wouldn't put it below the top of the boiler jacket in my opinion.

24" from the water line to the bottom of where the riser turns horizontal before it drops down into the header (higher is better) if you have the room

Hap_Hazzard

Figure out how many unions you're going to need for the wet return and start shopping around. Also think about where best to put them. If you can put them on vertical pipes above the water mine they'll last longer.

drewbert41

Progress:

Steamhead

Good start.

neilc

is there any concern with what looks like will be a horizontal reducer at what I think is the equalizer return there ?

Steamhead

Assuming that's what that pipe does. @drewbert41 , can we get a pic from that side?

drewbert41

My mains are 2 1/2 and they said to go with the biggest header I could so it is 3". How else should I reduce to the 2 1/2 and what is wrong with how it is done above? That corner was a mock up, but was the plan. I got all my custom sized pipe back from the mechanical shop yesterday.

drewbert41

@Steamhead OK, so I read about why horizontal reducers are bad. Would a reducing elbow be fine?

Steamhead

drewbert41 said:

@Steamhead OK, so I read about why horizontal reducers are bad. Would a reducing elbow be fine?

If that 2-inch pipe with the elbow and bushing on the end is feeding the steam main connection, no. It must be the same 3". Once it passes the tee(s) where the steam main(s) come off, you can use a 3"x2" or 3"x1-1/2" reducing elbow as long as it points down. This will keep water from backing up in the pipe.

drewbert41

@Steamhead this is what that side looked like. That makes sense. Right now I have one 2 1/2" main that goes up to the ceiling and about 5 foot later splits into 2 mains for the house and they are both 2".

I plan to run the two mains off the header\equalizer so I am thinking of running 2 1/2" from the tees to the ceiling and switching to 2" on the ceiling like the rest. So when I reduce that down it must be vertically and not horizontally correct?.

drewbert41

@Steamhead Also, the pipes coming out of the boiler are 2 1/2" and they are going to drop down to the 3" header. I am planning on reducing them into a 3" tee. This is ok because it will be vertical correct?

Steamhead

Having one 2-1/2" main coming up from the 3" header and splitting into two 2" mains will work, as long as there are no places where water can collect. It might be easiest to run each 2" main down to a 3x2 tee on the header, if that's the easiest way to avoid water pockets.

neilc

just so we're all clear,
the 3 inch horizontal header, must stay 3 inch, until it turns down, into the equalizer,
(same as the picture of the old, too low, header, is piped)
and bringing the 2 system mains down to the header, separately, is most preferable,
The 2 boiler risers, then the 2 system mains, then the equalizer, in that order, are the connections to the header.

drewbert41

@neilc Thank you for this explanation. So, pretend in this picture that the header is 3" and everything else is 2.5" Would reducers be ok where the red circles are?

Steamhead

Yes.

mattmia2

Think like water and think about where the restriction is from the reduction. Can the condensate back up behind it or will it flow through.

The order of the items in the header is important too so water will tend to go in one direction and steam in another.

drewbert41

Thanks guys, really glad I posted the update before I got it all put together!

JUGHNE

You could simplify by using reducing tees in your header.
Are you going to supply the two 2" steam mains with one 2 1/2" or will you put in two 2" main connections to the header?

As far as trapped water pockets, your steam mains above the boiler are usually the highest point in the steam main. So from that point the water would drain with the steam flow direction and all the way around the main.

neilc

like everyone else said, that last picture is good,
yes, reducers, or correct sized tees, can be at those red circles,
ideally, the 2 mains connect separately to the header, like in the picture.

drewbert41

Alright, we made some more progress today. I remember you guys saying a level header is ok, but a pitched one is an art. We got it all put together and realized it was not level. I put a level on it and it looks like it is pitched towards the mains\equalizer. I think this is the right direction for the pitch and I should just leave it instead of trying to level it yes? May have gotten lucky I hope?

Just have a few more 3" nipples to get custom made and I will be running my mains from the reducing tees. Thanks for the help.

Steamhead

If it slopes from the boiler steam connections down all the way to the equalizer, that's great.

JUGHNE

I have noticed on the same design of side outlet boilers that the push nipples inside the boiler are a smaller diameter than the 2 1/2" on the outlet.

If you remove the plug on the right rear tee outlet and look in side you might see what I mean. This is where you will skim when all done, floating the oils off the top of the boiler water.

I added a 2 1/2" x 1 1/2" coupling with nipples at that point.

This makes the skimming water rise above the top of all sections as it flows slowly out of the 1 1/2" nipple.

Otherwise is it flows out of the 2 1/2" nipple only the section closest to the tee gets water flow thru it as you skim.

A cap on the 1 1/2" nipple is recommended as it is easier than a plug to remove in the future.

drewbert41

One step closer. Trying to get this done before it gets cold.

drewbert41

Hey guys,

Couple grand in pipe, lots of heat, and busted knuckles later, it is all back together before the heating season. Thanks for your help.

I have ran it for about a week and have some oil to skim like was mentioned. Everything is running quieter and it should be more efficient.

I only have one issue. I used to have one main that split about 10 feet away from the boiler. I ran the mains straight off of the header independently. The second steam main is taking longer to heat up. The other day the pipe was hot but not the radiators. I have air hissing out of the radiators on that main.

I am wondering if maybe I need to make some adjustments, or if I am just running short cycles because it is not very cold and these will get hot when I do. I am sure insulating will help and that is the plan.

Thanks

mattmia2

Look at the main vent on the main that isn't heating. Does it exist? What is it compared to the other main vent? how do the main lengths compare?

drewbert41

The main vents are actually working now. Years past I was never sure unless I put my hand by them. Now I can hear them. Probably because my steam used to be so wet.

The pipe gets super hot all the way around the loop after some time. I will measure the lengths.