Tons of problems, not sure where to start

shroos

So I just recently purchased a new home, and as part of the conditional offer I made, the sellers replaced the furnace, so it is literally brand-new as of mid-September. I have an oil-fired Beckett burner attached to a Dunkirk steam boiler with a pass-through hot water coil. With that info, I'll begin my list:
1) Temperature control is almost non-existent. Sometimes the furnace will run and run for hours despite reaching the set temp on the thermostat, and more alarmingly but less frequently, doesn't run when below the set temp. I replaced the thermostat with a newer model and have already made sure it is set correctly. I also checked the wiring diagram and connections on the burner control unit amd everything appears to be in order, so my only thoughts are the wiring itself is shorting somewhere in the wall, or the control unit is faulty.
2) The sight guage constantly fills to the top if I manually cut the power to the furnace, and I'm concerned this means there's a leak in the pass-through coil. The only other possibilities I can think of is that either the sight guage is just not accurate, or the ball valve on the cold water in line may be leaking, but it doesn't make any noise or vibrate, so I can't be certain without replacing the valve.
3) Just this morning, as mentioned above, the furnace would not turn on despite a call for heat from the thermostat. When I got home from work a few minutes ago, it had clearly been running for quite some time as the thermostat was reading 81°F, so I went downstairs to manually turn off the furnace and noticed the pressure guage climbing alarmingly fast. It was at 5 psi when I first looked and less than a minute later it hit the cut-in setting of 8 psi and automatically shut down. I'm at a loss on this one.

Any help would be appreciated! Thanks

SuperJ

Can you post some pictures?
Perhaps try valving off the dhw coil, and resetting the water level to the correct level to see if it holds.
As far is it not turning on, perhaps it it being held out on a safety, is your pressure gauge good working order (clean pigtails, zeros out, etc)?
What does it read when the boiler is firing steady state, and off.
Is there an aquastat maintaining the boiler at temperature for domestic hot water production? It almost sounds like the boiler is running only on the aquastat and ignoring the thermostat completely.
When the boiler runs can you check to see if it corresponds with a DHW demand?

Jamie Hall

It sounds as though you have multiple problems, to put it mildly. I wouldn't be a bit surprised if at least some of them were traceable to a poor installation, but before I slander someone unnecessarily, could you take a few photos of the boiler from at least three sides, showing the boiler and the piping attached to it up to where the steam mains branch off around the house?

To attack the last point first... the gauge you were looking at is the standard 0 to 30 psi gauge? And it was at 5 when you looked and climbed to 8 when the boiler shut down on, presumably at the "cutin" setting? If that is a moderately standard pressuretrol (a blue grey box with a graduated scale on it) that setting should be a little less than 1 psi, not 8. 8 is astronomically high in steam heating terms. If the installer left it at that setting, it's clear that he or she is clueless about steam heat... hence the comment in paragraph 1 above. You can adjust that to where it belongs -- there is a screw on the top which you can turn to move the indicator up or down; turn it so the indicator is just a bit below 1 on the scale.

The good news is it would seem the pressurestat turned the boiler off...

The level in the sight gauge shouldn't change much over time (t may bounce when the boiler is running), and should never rise over time if the valves feeding the boiler are off. There could be a leak in the domestic hot water coil, although there certainly shouldn't be on a new boiler, or the ball valve on the fill line may be leaking slightly. Is there an automatic feeder? That could leak slightly, too. In any event, somethings feeding water to the boiler when it shouldn't be, and you need to find it and stop it. Sight gauges are simply not inaccurate; if they work at all (there are times when they don't) they are accurate.

As you observe, the oil burner should turn on when the thermostat calls for heat, and turn off when the thermostat is satisfied. It's possible the control unit is faulty, although that is highly unlikely in a new unit, and almost never results in a false on condition -- more often a failure to run at all. There are ways to diagnose that.

Bottom line: I suspect that you need to get someone in there who really knows steam to look at the whole situation and put things to rights. Where are you? It may be that we know a reliable contractor nearby.

shroos

This is the pressuretrol and PSI guage

shroos

Boiler and pipes from front and both sides. I live in north-central NH

shroos

Oh, and I do not have an automatic feeder for the water, I have to manually turn a ball valve occasionally to fill the boiler. It's possible I may have accidentally overfilled it, but I haven't had if off for long enough to comfortably drain it without worry of scalding myself. The sight guage is nearly full and when the burner is operating it looks nearly empty, but there are lots of bubbles and occasionally some jumping water levels

shroos

SuperJ there are a lot of terms I'm not familiar with in that post, but I have considered that it may be running incessantly on account of demand for hot water and it doesn't appear to be the case. When all water using devices and faucets in the house are off, it will still sometimes run past the thermostat setting

KC_Jones

First it's piped incorrectly
Second the pressure is way too high, that should be set pretty much at the bottom of the scale.
I think a start may be to trace out wiring as Jamie mentioned and make sure there isn't a short somewhere to address your immediate problem.

Jamie Hall

In the picture showing the sight gauge, the water level is about where it should be when the boiler isn't running. So that's good. And has been said the pressuretrol is set way too high. But the adjustment screw is right there where it should be, so have at it with a screwdriver. Just don't go too far down -- stop at 1 for the moment.

The boiler may run when there is a demand for hot water, but it shouldn't run so much that it produces steam. The control for that is the "aquastat" which is on the same plate where the hot and cold water pipes go into the boiler -- kind of tucked in there. It has a control dial on it which I can't read in the photo. What is it set at?

One thing I'd like you to try: with the boiler off and no hot water running, go to the thermostat and turn it up. The boiler should start with a minute or so. If it does, let it run for 5 minutes or so and then turn the thermostat back down -- well down, below the room temperature by a few degrees at least. The boiler should stop within a minute or two. If that test works, at least we know that the thermostat and the boiler are communicating -- at least part of the time.

I'll have more thoughts.

There is one bit of bad news: your part of New England is kind of lacking in good steam people, for some reason. I suspect, though, that much of the problem is a controls and wiring problem, rather than strictly steam, and if you can find a good -- really good -- heating contractor they will be able to help.

I wouldn't worry much about the boiler piping at the moment. as @KC_Jones says, it's not right, but let's get some simpler things out of the way before we worry about that -- if we even need to.

shroos

I turned down the pressuretrol setting to 1 psi, and the aquastat is set at 180. As far as the thermostat controls, the burner is in one of the phases where it runs constantly despite being way over temp. I have it set to 60°F but room temp right now is 73°F and the burner is still trying to run constantly. It cuts out now every minute and a half or so, presumably from the pressuretrol change, and comes back on about a minute later

Fred

You have a short somewhere, either in the wiring or you have a wire touching across terminals at the T-stat end or the boiler end. I assume you only have one thermostat for this system, right? Also, if the boiler continues to overfill with water and you don't have an auto water feeder, turn the cold water supply for the hot water coil off for a day or two and see if that resolves that problem. If so, that coil is leaking in to the boiler.
After you get these more immediate issues resolved, clearly the boiler needs to be skimmed to stabilize the water level.

lchmb

where in North central NH? As mentioned it needs some work.. repiping will be in your best interest..and repairing the control issues will save you money.. I may be able to direct you to someone who can help you out..

Fred

It wouldn't take a lot to correct the way the boiler risers connect to the header. I also don't see a skim port. It is interesting that is a Dunkirk boiler with the riser tappings on the top of the boiler rather than on the sides. Has Dunkirk redesigned their boilers?

shroos

Yes only one thermostat for the entire system. I will recheck the wires, but that was my first go to and it's been rechecked several times since. I live in Franklin, it's north of Concord, west of Laconia, and south Plymouth

Fred

shroos said:

Yes only one thermostat for the entire system. I will recheck the wires, but that was my first go to and it's been rechecked several times since. I live in Franklin, it's north of Concord, west of Laconia, and south Plymouth

Did you also check the aquastat wiring? Something is calling for heat or shorted, especially since it does shut down from time to time.
I see the thermostat wire is stapled to the floor joist. looks like metal staples. Are you 100% sure one of those staples hasn't nicked the wires, shorting them out?

Jamie Hall

The way to check the wiring is quite simple, really -- and if it's continuing to run, it's something you need to do. Disconnect the thermostat wires -- both of them -- and the aquastat wires at the control box on the boiler. The burner should shut down. Now connect a jumper between the two thermostat terminals at the control box. The burner should run. Disconnect that jumper, and reconnect the thermostat wires only -- not the aquastat -- and go to the thermostat and disconnect it. The boiler should not be running. Now connect the thermostat wires together at the thermostat end. The boiler should run. Disconnect, and the boiler should turn off. If either the boiler doesn't run with the thermostat wires shorted at the thermostat, or won't quit running when the wires are disconnected, there's a short somewhere in the thermostat wiring. Don't try to find it -- run a new wire. Now reconnect the thermostat and call for heat; the boiler should run. Stop the call and the boiler should also stop. If that doesn't work properly, the thermostat may be the problem.

If you haven't found the problem in the thermostat wiring and thermostat, it's time to do the same thing to the aquastat wiring and the aquastat.

It's best to make the test connections and disconnects with the boiler switch off, and then turn it on to run the test. It does mean running up and down stairs, or getting a helper and a radio, but the boiler controls will be happier.

I might also add that a visual check of the wiring is all well and good, but the problem may be hidden.

Remember that the boiler does not have a mind of its own. Unless there is something seriously wrong with the control itself, which is unlikely, the burner will only run when there is electrical continuity between the two thermostat terminals. Period. Clearly you have a situation where you have electrical continuity when you don't want it.

Any luck?

SuperJ

@Jamie Hall said it better than me. Deleted

Brewbeer

Do we know if the boiler is correctly sized to the radiation?

Fred

@shroos , I also see what looks like a very nasty splice in that thermostat wiring connecting it to some very old wire. Hard to tell from the pictures but it doesn't even look like those splices are taped???

JUGHNE

Also the dry returns where they drop to the floor look to have a tee with a "vent plug" installed.

lchmb

shroos I sent you a message. I'm 20 minutes north of you and know some good local steam guys.. I'm sure one of them can get you fixed up..

SuperTech

I don't see a test hole in the flue pipe anywhere, I know you have more urgent issues but please make sure that the burner is set up correctly by a technician using a digital combustion analyzer.