NEW BOILER PIPING FOR HYDRONIC HEAT - USE TYPE L OR TYPE M COPPER?

FeelingColdColdCold

Looking for advice. Any concern with M and pinhole leaks or save money and use it?

hot_rod

Type M is fine tor hydronics
pin holes are most often caused by aggressive water, excessive velocity, un-reamed copper

Fin tube baseboard us even thinner wall than M type and it can last 50 years, plus

leonz

Is this for close boiler piping or running pipe to baseboard connections?

Close boiler piping should be steel pipe as it tolerates expansion from
heat more readily and is thicker.

pecmsg

leonz said:

Close boiler piping should be steel pipe as it tolerates expansion from heat more readily and is thicker.

I’ll disagree!

jumper

So long that it is soft.

HVACNUT

M is fine for heating but some municipalities like to strut their feathers and require L, so check if it's going to be inspected. 

Mad Dog_2

M is fine.  We have some municipalities here on Long Island 🏝 that still don't allow PVC on Residential DWV, AAVs, Wet venting. Try fighting them on it...Mad Dog 🐕 

JohnNY

leonz said:

Is this for close boiler piping or running pipe to baseboard connections?

Close boiler piping should be steel pipe as it tolerates expansion from
heat more readily and is thicker.

This isn't correct. Are you thinking of steam?

Derheatmeister

Type "M" should be fine unless you are Pro Pressing..They like to see "L"
Pinhole leaks can develope due to many factors:
1. Errosion:If the pipe is not deburred it causes Cavitation which errodes even heavier gauge piping. Especially on Recirc lines or piping systems with high flow rates this becomes a issue.
2. Aggressive System fluid: Glycol that has deteriorated generally becomes aggressive/Low in PH..A Low PH in conjunction with Oxygen ingest can eventually become a "Pinhole" situation.
Well water can sometimes be low in PH depending on the Aquifer it came from.
4. Galvanic reaction: Disimilar metals are constantly on a battle with each other.We have seen pinhole leaks in Domestic waterlines that were caused due to system repairs from the Water Company which allowed fine metal shavings to enter the homes Copper piping.
These metal shavings would "Eat" a Pinhole that looked like someone drilled a small hole into it.
A Whole house partical filter can help reduce this.
Galvanic reaction is also someting that never sleeps in a modern hydronic heating system:
Maintaining Glycol levels higher that 20% while also using DEIONIZED water will ensure proper inhibitor levels
An other way to reduce this galvanic battle between the disimilar metals is to reduce the system fluids Electrical Conductivity (EC). By reducing the EC this does not allow the disimilar metals the to "see" each other and therfore they will not react toward each other .This is very easy to achieve by installing just deionized water...No Chemicals needed

Derheatmeister

HVACNUT said:

M is fine for heating but some municipalities like to strut their feathers and require L, so check if it's going to be inspected. 

How do the municipalities react toward the very thin copper Baseboard ?

Derheatmeister

jumper said:

So long that it is soft.

Do not understand why it has to be soft . Can this please be explained?

leonz

JohnNY said:

leonz said:

Is this for close boiler piping or running pipe to baseboard connections?

Close boiler piping should be "black" steel pipe as it tolerates expansion from
heat more readily and is thicker.

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This isn't correct. Are you thinking of steam?

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I am basing this on what I have read in both "Classic Hydronics" and "Pumping Away" in building my pump module for my coal stoker boiler exactly as Mr. Holohan suggested and why I used black iron pipe to build my pump module.

No one that installs coal stoker boilers recommends using copper for close boiler plumbing.

STEVEusaPA

leonz said:

...No one that installs coal stoker boilers recommends using copper for close boiler plumbing.

Not coal, but I always get a kick out of your persistence in shoe horning that in whenever you can.

Kickstand55

Leonz, what are you trying to do? Tell us the whole story and include pictures. We like pictures.
If you're trying to re-invent the heating system, it might come back and bite you. We can help you, or at least, try.

leonz

My piping/pump module was done before the plumbers came and ripped out the out the old boilers.
I have no had leaks in 8 years except for the pair of propress fittings they installed on the domestic coil that blew apart and drained my well dry in the middle of the night the year the coal stoker boiler was installed.

I have talked about my keystoker coal stoker installation and the faulty hydrolevel 3250 plus controls here on the forum previously.

In 2015 when they installed the coal stoker the hydrolevel controls installation/owners manual stated that its controls were ment only for cold start gas boilers.

I did not know I was in trouble until I could not find a physical address in china for the 6 inch pressure gauge manufacturer or for hydrolevel.

Ripping out the digital controls keystoker supplied and installing the Honeywell L8124L, McDonnell & Miller RB-122-E and Dwyer 4 inch triple gauge to replace the faulty chinese made hydrolevel junk and chinese made pressure gauges that nearly caused my boiler to explode was the best thing I did.

I no longer recommend keystoker coal boilers to anyone or if anyone intends to install one of thier coal stoker boilers I tell them to not use the keystoker supplied controls and replace them with mechanical honeywell aquastats and Dwyers American made gauges.

If Keystoker had simply stayed with 3 single aquastats to control its coal stoker boilers for pumped heating systems they would not have had 70+ hydrolevel units returned as defective.

After the same plumbers inspected my nieces steam boiler saying it simply needed repairs to pass inspection then "did the repairs" the plumbing inspector failed it and she had to buy a new steam boiler.

EdTheHeaterMan

Derheatmeister said:

HVACNUT said:

M is fine for heating but some municipalities like to strut their feathers and require L, so check if it's going to be inspected. 

How do the municipalities react toward the very thin copper Baseboard ?

They can't think that far past the boiler room. They are tradesmen that could not make it in the field, so they took and past a Civil Service Test (the kind that the garbage collectors take) so they can vent their frustrations on successful tradesmen.

I apologize to the Garbage Collectors

Mr. Ed

EdTheHeaterMan

leonz said:

My piping/pump module was done before the plumbers came and ripped out the out the old boilers.
I have no had leaks in 8 years except for the pair of propress fittings they installed on the domestic coil that blew apart and drained my well dry in the middle of the night the year the coal stoker boiler was installed.

I have talked about my keystoker coal stoker installation and the faulty hydrolevel 3250 plus controls here on the forum previously.

In 2015 when they installed the coal stoker the hydrolevel controls installation/owners manual stated that its controls were ment only for cold start gas boilers.

I did not know I was in trouble until I could not find a physical address in china for the 6 inch pressure gauge manufacturer or for hydrolevel.

Ripping out the digital controls keystoker supplied and installing the Honeywell L8124L, McDonnell & Miller RB-122-E and Dwyer 4 inch triple gauge to replace the faulty chinese made hydrolevel junk and chinese made pressure gauges that nearly caused my boiler to explode was the best thing I did.

I no longer recommend keystoker coal boilers to anyone or if anyone intends to install one of thier coal stoker boilers I tell them to not use the keystoker supplied controls and replace them with mechanical honeywell aquastats and Dwyers American made gauges.

If Keystoker had simply stayed with 3 single aquastats to control its coal stoker boilers for pumped heating systems they would not have had 70+ hydrolevel units returned as defective.

After the same plumbers inspected my nieces steam boiler saying it simply needed repairs to pass inspection then "did the repairs" the plumbing inspector failed it and she had to buy a new steam boiler.

Don't hold back @leonz ... tell us how you really feel!

Jersey2

The installers used M pipe in my system but I much rather have L. They did use pro press fittings on the L pipes and I can see how the ends of the pipes deformed from the crimp tool. But like others mentioned, when I was getting pin hole leaks from my well water it was on the domestic water copper pipes that got continuous 'new' water, not the closed loop boiler pipes.

Mad Dog_2

That super this copper tubing on baseboard elements are always the first to split in a freeze up.  Mad Dog 🐕 

leonz

EdTheHeaterMan said:

leonz said:

My piping/pump module was done before the plumbers came and ripped out the out the old boilers.
I have no had leaks in 8 years except for the pair of propress fittings they installed on the domestic coil that blew apart and drained my well dry in the middle of the night the year the coal stoker boiler was installed.

I have talked about my keystoker coal stoker installation and the faulty hydrolevel 3250 plus controls here on the forum previously.

In 2015 when they installed the coal stoker the hydrolevel controls installation/owners manual stated that its controls were ment only for cold start gas boilers.

I did not know I was in trouble until I could not find a physical address in china for the 6 inch pressure gauge manufacturer or for hydrolevel.

Ripping out the digital controls keystoker supplied and installing the Honeywell L8124L, McDonnell & Miller RB-122-E and Dwyer 4 inch triple gauge to replace the faulty chinese made hydrolevel junk and chinese made pressure gauges that nearly caused my boiler to explode was the best thing I did.

I no longer recommend keystoker coal boilers to anyone or if anyone intends to install one of thier coal stoker boilers I tell them to not use the keystoker supplied controls and replace them with mechanical honeywell aquastats and Dwyers American made gauges.

If Keystoker had simply stayed with 3 single aquastats to control its coal stoker boilers for pumped heating systems they would not have had 70+ hydrolevel units returned as defective.

After the same plumbers inspected my nieces steam boiler saying it simply needed repairs to pass inspection then "did the repairs" the plumbing inspector failed it and she had to buy a new steam boiler.

Don't hold back @leonz ... tell us how you really feel!

=================================================================

If they had continued to use honeywell aquastats; even the single aquastats they would not have had 70 plus units returned as failed units. They have not helped themselves by placing the hydrolevel units right above the fire inspection doors exposing the units to excess heat.

They claimed that they could no longer buy the honeywell triple aquastats and they were wrong about that as I bought 2 of them. I have a spare L8124L sitting in my parts box that I will probably never need based on my past usage of another honeywell unit that controlled both the hand fed boiler and the beautiful Buderus logan G204 oil boiler before this. I bought the buderus boiler based on a plumber telling me the avco lycoming boiler was leaking and I gave this boiler to a friend and he told me the avco unit had no leaks so I spent/wasted $3,600.00 because the plumber I trusted told me it was leaking.

jumper

So long that it is soft.

Mad Dog_2 said:

That super this copper tubing on baseboard elements are always the first to split in a freeze up.  Mad Dog 🐕 

Tube was expanded into fins. So it's already stretched?

PeteA

Just for my own knowledge since this thread seems to have taken a few different directions. Is the use of the L or M mainly just a cost savings difference for the close to the boiler piping? I saw someone mention that the thicker wall L is better if pro-pressing due to pipe distortion being possible with the thinner wall M. That makes great sense, but in general if someone was sweating the pipe and not using the fancy new tools would it just be about the cost between the 2 types? I 100% understand that in the trades costs add up and as long as the lower priced item is suitable then saving on jobs compound into a good amount of money. But on the one off job is there a difference if L or M is used if being joined by sweating?
On one of my other thread I was given great info on the pipe size I need and also advised I could use copper, pex or steel. so if they are interchangeable does the bottom line come down to cost and time?

Thanks
Pete

hot_rod

Type M us adequate for residential boiler piping.
we use type L if we are doing any bending of the  tube. 

If course if you are only looking at 20-30’ of near boiler piping, the cost difference to use L may let you sleep better at night🥴

SummitMechanic

It all depends on BTU and flow rate, Type M is just fine for almost all residential applications until you get to or over the size of 1" copper and are using pro press instead of sweat. In commercial settings 1 1/4 or over no matter the application need to be L due to flow rate and btu. to be safe though, If it is being pro pressed it will be preferably type L.

Mad Dog_2

When cost is an issue for a client, M copper is fine...nothing wrong with it.  If $$ is not an issue, they're getting L copper. Some Municipalities insisted on L only...even for heat.   I once installed K (the thickest wall used on underground water service lines) at a Client's insistence.  Its their $$$....Mad Dog 🐕 

Larry Weingarten

Hi, I think I'll add that velocity in the line matters. If you might have over four feet per second you're taking a greater risk going with the thinner copper, as erosion corrosion is real. Intermittent high flow is not so much a problem as flow many hours a day.

Also, when comparing copper and PEX, consider the inside diameter. PEX, with its thicker walls, might need to be sized up to handle the flow.

Yours, Larry