Troubleshooting Main Electric Panel Water Infiltration/Boiler Control Issues

D107

With our new Peerless MI-03 boiler, there have been several control issues with our Hydrostat 3250+. One has been two instances in five months of blocked vent shutoff switch activation--which the reset button corrected immediately. I have already been advised on the wall about possible HVAC-related causes.

Two is the LWCO indicator light going off twice for no apparent reason. Water pressure is constant, and no water loss from system. The first time it happened we came back from vacation--probably some thunderstorms in the interim--I turned the boiler power switch off and on with no effect. But when I turned the remote boiler switch on the basement stairs off and on, the indicator light came on again.

This second instance, nothing seems to correct it; it happened when our electrician turned the main breakers off for some other testing. When the electric was turned on again, the light for the LWCO did not light. (Note that on startup, the RED LWCO light always shows for a few seconds as part of the rebooting, but then goes out.) I guess it could be as simple as the LWCO 'on' little lightbulb itself being defective or loosely connected.)

Since we recently had a new water main, I had an electrician transfer the ground from the old galvanized line to the new copper one, and in the process he took off the main basement panel cover and discovered efflorescence on the two main breaker contacts, and some brown debris at the bottom of the panel. HIs conclusion was some kind of water infiltration. It was a humid day and nothing was visibly wet that we could see, so we ruled out dripping from water pipe condensation.

There are no water pipes there--it would only be heating pipe nearby that leads to two rads in attached porch. There should be no way water could come from the upstairs living room or attached on-slab porch. So he took off the meter outside and found both the street and house side contacts loose, which took a few turns to tighten. He felt that that looseness could have permitted water to travel within the sheathing (or possibly outside it?) to the panel. This 200 amp system was upgraded in 2006. He showed some cracks at the end of the rubber sheathing of the main lines--said, if I'm recalling correctly---the lines have some kind of insulation in them that can turn a yellowish if water gets in. Said the contacts being so loose could have caused an issue if we had subjected the system to a heavier load than we do.

Plan is to replace the line from the meter to the panel and the panel itself. I'm not sure why just the line couldn't be replaced and the panel cleaned. Also I don't know if it's proven where the water or humidity is. Note we have a de-humidifier on 24/7, and while I've seen efflorescence on our opposite basement brick wall, never anywhere else. Note also the panel is behind a sheetrocked wall with an access door.

So even though I can't say I've noticed any serious issues with our electricity--very occasional light-flickering--it does make me wonder if that could be having any effect on the boiler controls--admittedly more finicky than our old t-stats and prior 1981 WM boiler that had no spill switch or LWCO.

JUGHNE

There was a case for me where the overhead point of attachment (house knob), was above the weather head on a pipe riser. Not the preferred installation BTW.

Rain water on the overhead line would wick down the loop and get into the individual wires in the pipe. The water was actually inside each wire between the copper and it's insulation.
You would think this would not get into the basement panel, but pulling the meter and observing this during a rain storm, (not a DIY idea BTW), the water would drip out of one of the line conductors at the top lug and enter the load conductor on the lower lug and find it's way down into the main breaker.

Increasing the loop drip at the very top above the weather head cured the problem.

Just about all new services I install are piped raceway jobs.
On them you have to seal the raceway where it comes thru the wall into the basement or condensation will occur.

I just changed out a 51 year old 200 amp sub-feed panel in a school house. The interior steel components were rusted.
The main concern was the steel screws that held the copper buss bars together. I believe the entrance pipe was originally a riser up into the cold attic and with the panel in the kitchen store room, the humid air would rise and then rain back down on the panel.

I can't see that loose meter socket screws would allow water into the cable.......check your weather head loop.
If your panel in on a cold concrete wall it could cause condensation inside the box. It is a reason to mount on plywood for a bit of insulation behind it. Also to have that cavity open to the room conditioned air.

D107

@JUGHNE Attaching some photos of the outside connections. Drip loop seems about 8-9 inches which I would think would be ok. It does look to me like some peeling electrical tape or other covering is coming apart at the head. And above the meter box you can see some of the black caulking has a crack in it.

It also looks like the raceway is sealed pretty well but I'll go out and take another closer look. Panel is on two layers of plywood which should be ok. Though I just recalled that it's been about only 18 months since we installed an access panel door in front of the panel, thus sealing it tighter than it ever was before. Perhaps a little 5x5" window screen in the center of the plywood access door will ventilate well enough.

I will send some photos later of the panel itself to see if people feel it warrants replacement.

D107

@Jughne If by meter socket screws you meant the outside ring to hold the meter, the electrician wasn't referring to that. It was the four screws or nuts inside the meter box that tightened the exposed ends of the wires. See generic photo newly attached.

To my untrained eyes, the wires leading into the panel seem fine, though not sure the silver wire (neutral) should be touching the two copper lines (grounds?). The brown dusty stuff on the bottom looks mostly like insect eggs I've seen form on some of those black 'wall warts' plugged into outlets though I do see some brown rusty areas on the bottom right of the box where some cutouts are.

Once the source of the water/humidity is found, couldn't we take care of that on the outside, clean up the panel and leave everything else. At worst replace the line from the meter to panel? At this point not really sure if this is just not humidity building up from being enclosed.

The final question would be does this have anything to do with any of the Hydrostat's issues? I guess we'll secure the electric system first and go from there.

JUGHNE

Your neutral connection looks like it could be in trouble.
IMO water may have followed the braided neutral from the meter socket or even thru the weather head as in the scenario i described above.
Your weather head splice connections are not water tight, they are designed for water to pass thru the cover. They are at the place where water could run down and wick/capillary action pull water into the wires. Sounds like a reach to believe but it happens.
Or the top of the meter socket sealing is leaking, (that might not be a rubber gasket compression fitting that it should be) and water follows the cable into the panel and drips on top of the neutral.
This looks to be aluminum wire into an aluminum lug and the panel has aluminum buss bars. None of these mix with water very well.

Your neutral may be "baked out" and give you a sketchy connection. If you lose it then 120 voltage has no center reference and one leg could rise and the other fall.
Also the neutral and grounding should be connected together, without a good neutral from the utility your grounding wire will attempt to do it's job......possibly tricking your LWCO, which is a probe in the water needing a good ground with no current flow on it.

I would suggest replacing the panel. You can probably get the same box, just replace the guts and reuse your small CB's.
If water has gotten into the main CB it may not trip if needed and may not shut off both legs if you use it as a disconnect switch.

EBEBRATT-Ed

The most likely issue is the "duct seal" that is the sealing compound on the top electrical fitting is cracked on the meter socket. That is the most likely place for water to get in. It will drip down onto the wire feeding the panel and go right into the panel . Happens all the time. While that fitting has an internal gasket as @JUGHNE mentioned they are not 100%

Also, at the weather head the splices between the house wires and the power company wires those splices are supposed to be at the lowest part of the drip loop. While this is not always the case the splices being low helps water drip off so it will not enter the house wires

If your panel has aluminum buss bars they could be oxidized from the water. Copper buss bars are better you can buy a panel with copper buss bars at almost the same price as aluminum

D107

@Jughne @EBEBRATT-Ed Thank you both for your valuable information. I did go out and temporarily caulked up the crack in the sealing compound just as a precaution.

So would you replace any line below what turns out to be the source of the leak or just make sure everything is sealed? Going to try to get this repaired asap.

And not only install a copper buss bar, but also replace the braided aluminum neutral with copper as well?

And if in fact a problem with a neutral can render the main breakers inoperable in shutting off power, then it seems any new panel should have a separate throw lever that cuts off all power.

Makes me wonder how many homeowners are totally unaware they may have these kinds of issues going on. I felt secure since we upgraded in 2006 with a brand new box etc. but it appears some corners were cut. Not to mention potential effects on HVAC and other equipment. Or Safety.

EBEBRATT-Ed

There is nothing wrong with aluminum wire (braided neutral). Basically you need a competent electrician to go through the service equipment and do what it needs. It is difficult to tell what you need without seeing everything.

Service equipment should be good for at least 20 years, most last much longer so yours having problems after 13..you got short changed a little.

The most common issue is water getting in due to the duct seal on top of the meter or deteriorated SE cable...your cable looks ok. Cable on the north side of a house lasts longer than cable on the south or west side.

To keep the water out:

Weather head installed vertical (which yours is)

deep enough drip loop with splices at the low point

watertight connector on the top meter socket connection and duct seal (which you have although deteriorated)

weep holes in the bottom of the meter socket to let any water out.

Caulk around meter socket top and sides, leave the bottom open

I would change the panel as that has seen some water. The cable and the meter socket need inspection

pecmsg

That Duc Seal is drying out.

Find out how much extra to just run conduit to the weather head? This issue will be solved once and for all!

BTW
In this area that Neutral must run unbroken thru the meter housing!

D107

@pecmsg @jughne When pecmsg you say the neutral must run unbroken, that doesn't mean it can't be spliced right? Otherwise, if it was decided not to replace the entire line from weather head, but just from the meter box into the panel that would be a problem, yes?

I'll ask my electrician about using conduit.

JUGHNE

The continuous neutral from weather head to panel would be hard to do with that cable. It must be a local requirement for his area. Could fairly easily be done with the pipe job.
Though this adds credence to the importance of a solid neutral connection.
Older smaller meter sockets had only a single lug for the neutral connection and a continuous wire was almost mandatory, it was often #6 solid bare copper.

If you go for the piping install, IIWM I would raise the new weather head well above the wall connection for the utility drop.
This ensures enough drip loop to avoid the situation I describe above.
The aluminum buss bars in the panel would be OK if kept dry.
You might save by just changing the interior of the panel.
That looks like a Homeline by Sq D....probably no copper buss options. Often copper buss bars are tin plated and look to be Aluminum.
IMO, it is better to use copper wire into the house. Often I used Al wire to the meter socket and then copper to the panel, FWIW.

D107

@Jughne Yes, panel is a 200 amp HOMC30UC Panel Series 501 (Homeline, SquareD.com). Electrician told me that having copper buss bars would raise price considerably. I'll have to ask around locally and see if that's true. You seem to be saying that if water ever did penetrate again, copper buss bars would be superior. Paying a little extra now would seem to be wise. Copper into the panel from meter--maybe 20 ft, can't be too much more expensive.

EBEBRATT-Ed

@pecmsg
I would be curious to know what location wants a continuous neutral. Unless it's run in pipe that would be pretty near impossible with cable as @JUGHNE mentioned

Sounds like an inspector making up his own rules

@D107,

copper buss bars are common in panels. Just go on line to home depot or lowe's and you can compare prices between panels with aluminum or copper buss. If you want copper wire for the service entrance you would probably have to install the service in conduit.

I have never seen copper Service Entrance cable around here for ages. Doesn't mean it doesn't exist somewhere

JUGHNE

200 amp SEC would be quite pricey. 2/0 copper IIRC.

Does that aluminum look like 4/0 (200 amp residential size)

pecmsg

EBEBRATT-Ed said:

@pecmsg
I would be curious to know what location wants a continuous neutral. Unless it's run in pipe that would be pretty near impossible with cable as @JUGHNE mentioned

Sounds like an inspector making up his own rules

Suffolk Co NY
Failed my install. Listed verse and chapter, don't have it anymore. Yes continuous from weather head to panel thru meter housing.

woobagooba

Shortly after we took possession of our current house, a trip to the basement during a heavy rain revealed water POURING out of the electrical panel. The cause was DucSeal failure at the top of the meter socket. Looks just like yours. Replacing the DucSeal solved the issue. Many years later we replaced the weathered service cable with a new weatherhead.

EBEBRATT-Ed

@D107

Why does 1 picture of the meter socket show it on vinyl/aluminum siding and the other on exposed wood siding run at 45 deg?

@pecmsg, Not doubting you at all. Most inspectors I have dealt with in 40 years are pretty reasonable. But I have run into a few looney's. I wonder what they would do on a wiring method change? For instance SE cable from the weatherhead down and conduit going in the building or vise versa.

I just did my house over 150 amp meter main outside. 2/0 Alum. SE cable down to the meter main. 1/0 copper out of the back of the meter main in 1 1/2EMT to the indoor sub panel

D107

@EBEBRATT-Ed The meter on exposed wood siding--a generic shot-- I posted to clarify to Jughne about which connections the electrician found to be loose in the meter socket. It was the screws/bolts that anchored both pairs (upper and lower) of cables. Electrician couldn't believe how loose they were, some as much as three or four complete turns. He felt that was potentially as dangerous as the infiltrating water. He tightened them up, and as a temporary measure I placed some rope caulking on that cracked sealer above the meter socket.

He did mention that here in NY at least he has noticed an issue with the new electric smart meters that when they are pushed into place there is a connection defect that over time will shorten their lifespan, perhaps within a decade.