Question: proper location for cold water fill piping--does it matter?

greg556

Hi--

What is the proper place for the cold water fill pipe (from the city water supply) to go into the near-boiler piping in a steam boiler? Here's a picture of my (residential) boiler--the water supply line enters the condensate return just before it goes back into the boiler. Is this okay? (Someone told me it should be connected to the Hartford loop--is that correct/important/either is fine?) If it should be connected into the Hartford Loop, WHY. Why does it matter? Also, the piping of the Hartford loop is copper--is that okay? Copper is okay below the water line? Thank you! Here's the picture:



Here is a close-up. The water supply line connects at the arrow, just before the boiler.



Thank you!

Greg

Jamie Hall

That's not really ideal, but it's perfectly alright. Hopefully you are adding so little water, so seldom, that it isn't a factor.

greg556

hi Jamie, thanks for writing back.  Why is it not ideal? And how does it impact adding water?  I add water every week, after I drain the sludge drains. What is the problem?  Thanks. 

ethicalpaul

I plumbed mine into my wet return just below my main vent which is about 7 feet away from my boiler. I can use it to flush my wet return.

The reason it's nice to have it a little more distant from the boiler than yours, in my opinion, is that as you fill the (probably) warm return pipes will warm up your cold fill water so it will be less likely to shock the boiler.

Jamie Hall

ethicalpaul said:

I plumbed mine into my wet return just below my main vent which is about 7 feet away from my boiler. I can use it to flush my wet return.

The reason it's nice to have it a little more distant from the boiler than yours, in my opinion, is that as you fill the (probably) warm return pipes will warm up your cold fill water so it will be less likely to shock the boiler.

Exactly what I was going to say...

greg556

The guy actually claimed it was a code violation. I'm asking if this is a severe problem. The return is far under the water line. I read somewhere else (don't remember where) that the one thing you don't want is to have the cold water in contact with the steam. (Which, it seems to me, might happen where you plumbed it?) The other possibility would be to pipe it into the bottom of the U before the Hartford loop. I can't see any *significant* difference between the two--something that would raise a safety or system longevity concern.

Let me show you something: here is the installation instructions for the boiler (a New Yorker). It looks to me like they tell you to put the boiler fill line in *after* the Hartford loop--I mean closer to the boiler than the loop. But I don't understand those diagrams well. What do you think? Thank you!



Thank you!

ethicalpaul

I read somewhere else (don't remember where) that the one thing you don't want is to have the cold water in contact with the steam. (Which, it seems to me, might happen where you plumbed it?)

No, mine is underneath 20-some inches of waterline, at the floor. No steam will touch it.

here is the installation instructions for the boiler (a New Yorker). It looks to me like they tell you to put the boiler fill line in *after* the Hartford loop

Yes, that's where they said. It's not that major but that's not where I'd put it.

ethicalpaul

If your installer comes back, have him show you how to remove the pressure control to clean out the pigtail. See if it will come off.

JUGHNE

You can't say he did not use enough pipe dope.

Hap_Hazzard

This is how I have mine plumbed. The red handwheel in the middle opens a valve that bypasses the autofeeder. The water enters about an inch below the bottom of the gauge and about 4" below the Hartford loop. Theoretically it could be exposed to steam if the water level dropped below it without triggering the autofeeder, so, to avoid that, make sure it's below the LWCO probe. I'm not sure why having steam there would be bad, because both valves can resist steam. You could always put a siphon tube (aka water seal) on the line if you're worried about it.

One thing I don't have, that may or may not be required by code, is a check valve/backflow preventer. I keep meaning to check my local code for that, but haven't gotten around to it.

ethicalpaul

It's required in NJ for sure. Is anything required in PA?

Hap_Hazzard

ethicalpaul said:

It's required in NJ for sure. Is anything required in PA?

I'm really not sure. I fixed a lot of bad wiring over the years, so apparently they don't require inspections. To be perfectly honest, I'm not even sure where to find the local codes. I've always relied on contractors to tell me, so I don't know where to look them up. I hope they're online somewhere.

EdTheHeaterMan

JUGHNE said:

You can't say he did not use enough pipe dope.

I can if he was going for the white pipe look! Needs to cover up more of that steel pipe and iron fittings. But I might have gone for painting over doping. But that's just me!

EBEBRATT-Ed

as far as I know no check valve is needed. I don't think a backflow is required unless you have an automatic fill but I could be wrong.

ethicalpaul

My NJ inspector definitely required it, I have no automatic fill. He said "we don't want boiler water getting into the municipal water supply" which I couldn't argue with except to wonder to myself "then why do you let the municipal water supply go to negative pressure??"

JUGHNE

Negative water supply pressure can happen quite easily.

Simple example is someone breaks off a fire hydrant that could be connected to a six inch main on your street. There goes your water pressure and could syphon water out of your house if you are in the right place in the system.

Or fire pump that gets connected to hydrant with non collapsible can pull a vacuum on the system.
That is why you use soft hose for that suction connection.

For my own system, the main outside had to be shut down for repairs and cut open.
As the residual water drained out it put my plumbing into a vacuum and dropped my boiler pressure to zero.

I since then have added a backflow preventer and LWCO and leave the water feed off.

Sh!t happens!

ethicalpaul

It happens at my house just about daily, you don’t have to convince me!

but no one is hitting hydrants

JUGHNE

I recall now you mentioning that. It was caused by pump switching?

In this state, by law, if the water system goes into a vacuum then the system must be chlorinated and water samples taken for several days....a real PITA to be avoided by the supplier.

You could inquire to state health water people about this requirement.
The supplier would avoid this if at all possible.

ethicalpaul

Yes I believe it is due to pump switching or something. I am ignorant of municipal water delivery. It goes down over a few seconds, then is at zero or negative for a few seconds, then it ramps back up to normal. But I didn't mean to hijack the thread--but yes I think a backflow preventer on a boiler is good and code should require it

Hap_Hazzard

Would this be the right thing to use?

https://www.supplyhouse.com/Resideo-BP900-1-2-NPT-Dual-Check-Backflow-Preventer


I assume the arrow is there to tell the water where to go, but what does the fitting marked "vent" go to?

JUGHNE

The vent would be piped down towards a drain or a bucket at least.

I assume that if the device fails it will dump the supply pressure out the vent.....IDK....not sure.
Hopefully someone here will comment.

There is also a design of this that has no vent, but how do you know it is working?

Jamie Hall

The vent can be left open -- that is exactly what it is -- or piped to somewhere else, if that's more convenient, However, it must NOT have a valve on it, and the outlet must be somewhere where it can be easily observed.

If water is ever seen dripping from the vent (never mind flowing) the device has failed and must be serviced or replaced.

JUGHNE

Yes, any piping for the vent should follow the same standards required for a relief valve drop pipe.

The bucket would be for observation of the dripping on failure.

Hap_Hazzard

What are the chances of it draining my boiler onto the floor or flooding my basement when it fails?

I'm tempted to just put a swing-check on it and call it a day.

pecmsg

Hap_Hazzard said:

What are the chances of it draining my boiler onto the floor or flooding my basement when it fails?

About the same as a burst pipe!

There are controls that can be installed to prevent / limit the damages.

ethicalpaul

My vent is just open, I'll let you know if it floods

Hap_Hazzard

pecmsg said:

About the same as a burst pipe!

There are controls that can be installed to prevent / limit the damages.

Would these also prevent a rusted-out water heater from leaking all over the place? If so, I'd be grateful for more information. At the moment all I have is a wet floor alarm that's not loud enough to wake me up if I'm upstairs in bed.

ChrisJ

ethicalpaul said:

It's required in NJ for sure. Is anything required in PA?

My inspector wanted it as well, but I honestly believe its not required in NJ if you're manual feed only.
My vent is wide open and has been since I installed it in 2011. I'd considered changing it....but I've been busy.




A benefit of running water that close to the boiler is it gets mixed with hot water faster which will drive O2 out faster.

The downside is it's easier to feed too fast and crack the boiler.

pecmsg

Hap_Hazzard said:

About the same as a burst pipe! There are controls that can be installed to prevent / limit the damages.

Would these also prevent a rusted-out water heater from leaking all over the place? If so, I'd be grateful for more information. At the moment all I have is a wet floor alarm that's not loud enough to wake me up if I'm upstairs in bed.

Yes
search potable water shut off systems. 

CLamb

ethicalpaul said:

"then why do you let the municipal water supply go to negative pressure??"

It doesn't have to go negative. It just has to be less than the boiler pressure. Here in Scotch Plains, N.J. Last time I measured the static water pressure it was about 80 psig. I don't think (and pray) that my boiler will ever get that hot.

JUGHNE

Hap, get a baby monitor to put by your bed with the transmitter in the basement.

I have heard of a tank splitting open and causing a tsunami in the room, but I think it is very rare.

From what I have seen, most just slowly leak and wet the floor.

Bad if leaking above a burner and snuffs the pilot out.

Hap_Hazzard

JUGHNE said:

Bad if leaking above a burner and snuffs the pilot out.

Actually, that would be a good thing. If it's a small leak I'd notice the water wasn't hot and go shut off the supply to the heater.

Hap_Hazzard

In case anybody else is interested, SupplyHouse has a whole category for Leak Detectors. If you look for cheaper options at Amazon or elsewhere, you should be aware that there are units out there, supposedly intended for this purpose, yet they don't have lead-free valves! Caveat emptor.

For me, the simplest solution is to pipe the vent to my water heater drain pan and install a water heater leak detector. This covers both possible leak sources.

Thanks, @pecmsg, for making me aware of these. I've worried about this for a long time.

STEAM DOCTOR

Fwiw, boiler water, without chemicals added, is not particularly unhealthy. Would not suggest serving it at a state dinner, probably doesn't taste that great. If code doesn't require and there are no chemicals in the boiler, I would be inclined to say that you are better off without the backflow. Backflows have a tendency to clog up. I would not be participating concerned about flooding. The vents drip, by design, when there is a backflow condition. Not very common. 

greg556

Thank you everyone! When the only comment anyone has about the near-boiler piping is the amount of dope the fitter used, you know he did a good job. One last comment--I am pretty sure it's better to go with the manufacturer's instructions than your own opinion about it!