My boiler is not firing.

jjustinia11

My boiler is not firing. I have everything on, I set the thermostat to 80 (just to get the boiler started), the circulator pump is running, I filled the boiler to a pressure of 10PSI but the boiler won't fire. The pilot light is on. When I turn my basement thermostat on the boiler fires, so I got the boiler temp up to 180. But then I turn that stat off and I am trying to only run the main zone and again the circ pump is running nicely, but the boiler is not firing. I suspect it is the settings of this aquastat, which appears to be set to zero. How do you set a boilers aquastat? I don't know what the numbers under it are (the 5 to 45 ones). I am reluctant to change anything here until I understand to avoid danger. Please advise.

nicholas bonham-carter

The aqua stat probably controls the temperature for all zones, so if the boiler will fire on the basement thermostat, and produces
heat, then it appears that the main thermostat has a problem.
Is the thermostat set to heat, and has it got fresh batteries in it?
Is it screwed firmly on to its sub-base, or has it been bumped?—NBC

HVACNUT

Does each zone have its own circulator?
Something is a little hokey. How did the boiler get to 180 with the basement zone on if the aquastat is turned all the way down?
Turn the dial on the aquastat until 160 lines up with the red indicator on top.
Is there another aquastat?
Does the boiler have a tankless coil for domestic hot water?
Where is that white/blue wire going?
Post some pics of the boiler from farther back and different angles.

newagedawn

sounds like a t stat, but try turning the dial to 180 to the red line ,apicture of the whole boiler would help!!!!,

HVACNUT

Just saw your other thread.
The aquastat near the top of the boiler ( vertical White Rodgers), set the to 160. Set the aquastat connected to the new circ to 140 and see what happens.
That zone might be air bound and needs to be purged.
Is the circ too hot to keep your hand on it? If so, purge.

captainco

The bottom dial should be the On differential. If the boiler temp is set for 180 degrees and the differential is set for 20 then the boiler has to drop to 160 degree before the burner comes back on. 20 degrees is the normal setting with fin tube radiators. Cast Iron radiators the setting may be 25 to 30 degrees.

jjustinia11

HVACNUT said:

Just saw your other thread.

The aquastat near the top of the boiler ( vertical White Rodgers), set the to 160. Set the aquastat connected to the new circ to 140 and see what happens.

That zone might be air bound and needs to be purged.

Is the circ too hot to keep your hand on it? If so, purge.

Thank you! I thought the white Rodgers was for the integrated hot water coil??? It say on it "hot water control" It was set to 165 I turned it to 160. The circ did get too hot to touch and the system is air bound. I bled half of the radiators but then it got too late. I put that to 140 and adjust the bottom dial to 20 as I have cast iron radiators.

THEN-I changed the batteries(even though there was no low battery warning) and set it to heat AND the burner turned on. I think maybe just taking the thermostat on and off may have helped. But actually I see know that the white rodgers controls the boiler and the boiler was above that temp. I spun it up to 180 and the boiler fired up, then I put it back to 160. and it went off. So I think it is just working normally and my aquatstat was set to the wrong setting of zero. I now have it at 140 with a 20 differential. should I leave everything that way???

HVACNUT

160-140 should be good. If the home has trouble keeping temp, raise them to 180-160.
You can purge the whole loop from the new purge station at the circ, then bleed any rads that aren't heating.
You have another thread concerning a PRV. Are you able to keep pressure on the boiler while purging?

jjustinia11

The pressure dropped to zero. I bled all the radiators and water is coming out. The pressure on the PRT is zero. That bar on it is bent. I have to manually go and lift it to bring the pressure back up to 10. I dont think it is working anymore. I am not sure it is letting any water in unless I manually do it. Should I buy a new one today?


The Radiators are still ICE COLD. After about an 45 min.


Also I what purge station? I jst have the isolation valves.

thank you for walking me through this. I appreciate it!

I have bled the system and the pressure is at 12PSI. The radiators are still cold. I just put the pump on hi. The water leaving the boiler is hot.

jjustinia11

So, the boiler is set to 180. Boiler temp is 180. The boiler pressure has been manually filled to 15PSI. The circ is running and I can feel the water moving in the pipe above it.
The Radiators are still cold!

I bled all the radiators. I even opened the overflow tank and opened the manual fill at the same time for a bit to drive out air.

I don't feel any water moving in the return pipe but the radiators are full of water when I bleed them water is coming out with plenty of pressure.

Dont know what to do...

JUGHNE

You say you have 2 zones? 2 T-stats?
If so then you have 2 zone valves? Or 2 circ pumps? Or 2 of each?

Didn't you have a "dead" pump with pipe that went nowhere?
What did you do with that?

jjustinia11

JUGHNE said:

You say you have 2 zones? 2 T-stats?
If so then you have 2 zone valves? Or 2 circ pumps? Or 2 of each?

Didn't you have a "dead" pump with pipe that went nowhere?
What did you do with that?

Yes, 2 stats, 2 cric, 2 aquastats, 1 boiler temp stat set to 190 now. The one dead cir (would have been zone 3, I pulled the wires out of the pump and it is dead)- I open the drain and no water came out, then closed it. The pipes were capped any way-went nowhere. There is water in the zone I am firing, it is hot, hot water is also backing up the return until it hit the check valves. All the return pipes are cold after the check valves on the zone I am firing. The pump is now running on medium, hot water is flowing and I can feel it downstream in the basement. But then the radiator are still cold.

I also diverted the water away from the water coil and opened those boiler valves to prevent pressure build up. I noticed hot water was backing up into the supply line and now it is not.


UPDATE: the water leaving the boiler is burning hot when I touch the pipe 10 feet past the circ pump. When I touch it 20 feet away from the circ pump it is not hot. I can feel the water moving, but lost all the heat.

this was not a problem last year...

Jamie Hall

Let's eliminate a variable or two -- you are having trouble with one of your zones. What about the other one? Does it behave normally? If so then clearly the problem is in that one zone.

And your description of temperatures indicates to me that you have very little flow in that zone. Some, but not much. Keep in mind that centrifugal pumps -- like yours -- have a "shutoff" head. That is there is a pressure difference across the pump beyond which they simply won't move any more water -- or at least very little.

So... What I'm looking for now is a flow restriction in that zone. Could be air bound, though you say that you have bled it and air binding will not, usually, kill the flow. However, it could also be a closed, or nearly closed, valve somewhere along the line. Check all the valves -- particularly check valves -- and make sure they are open.

JUGHNE

The pump pushes the water into the bottom of the boiler?
We are all confident the pump isn't installed backwards.

jjustinia11

Did I install it backwards!!??? The arrow is pointing up away from the boiler. Look at the picture. Should it be pointing back into the boiler? Also, How do I check the check valve, it is integrated into the pump.

JUGHNE

IIRC you are pumping into the bottom of the boiler with the hot coming out of the top of the boiler.

jjustinia11

> @JUGHNE said:
> IIRC you are pumping into the bottom of the boiler with the hot coming out of the top of the boiler.

I don't understand. Boiler has a pipe coming out of bottom then I have this pump, with an arrow pointing away towards the house. Is that correct?

JUGHNE

NO

jjustinia11

> @JUGHNE said:
> NO

Do I need to flip the pump over?

JUGHNE

Yes

jjustinia11

> @JUGHNE said:
> Yes

Ok. So that was the problem, the pump is supposed to pushe water into the bottom of the boiler and that forces water up and out to the radiators on the otherside. I will switch it right away. Good thing I put put in the isolated valves. Do we all agree that was the problem?

ratio

If it fixes the issue, it was likely the problem.

It's hard to guarantee that sort of thing without actually being there. Which way was the arrow on the old pump pointing? If it's still around, take a look at it.

FWIW, the pumps on my hot water system all point towards the boiler.

jjustinia11

> @ratio said:
> If it fixes the issue, it was likely the problem. :)It's hard to guarantee that sort of thing without actually being there. Which way was the arrow on the old pump pointing? If it's still around, take a look at it.
>
> FWIW, the pumps on my hot water system all point towards the boiler.

So fastest flip ever. All the other pumps including my old one pointed down. I flipped it and I flipped the impeller and it's is already looking better. Have to run to gym and will see more when I get back. Thank you.

HVACNUT

You likely have a flo valve on the supply side. If so remove the internal flo check in the circ. They're not designed for circs on a return.

jjustinia11

Well I flipped in 10 minutes (including fliping the impeller box) and the radiators are hot already. Although, I had to turn the aquastat down to zero to get it to spin, maybe that is why it was the way I found it. Maybe the aquastat is bad. but it is working the way it was last year again. thankfully I had the iso valves. your advice has paid off. Thank you!

JUGHNE

Sorry for short answers, was on the phone.

Nice to have valves isn't it?

The bulge on the back of the pump is where the water goes in, if you have it off you can see which port it connects to. The other port is where you can see the impellor and is where the check valve is to prevent unwanted flow thru the pump.

Today pumps should pump away from the boiler, for correct installation.
Years ago (your installation) pushing into the boiler, (pump on return) was the norm.
If you want the full story read "Pumping Away" Dan Holohan.

ratio

Great news.

I will now go so far as to state that the pump was probably supposed to point towards the boiler.

JUGHNE

Ratio, you aren't really into politics or anything like that are you?

Sometimes arrows are rotation, not necessarily flow directions. Usually is flow though.
The bulge in the back of pump that goes to one of the flanges usually tells me that is the suction.

jjustinia11

> @JUGHNE said:
> Ratio, you aren't really into politics or anything like that are you?
>
> Sometimes arrows are rotation, not necessarily flow directions. Usually is flow though.
> The bulge in the back of pump that goes to one of the flanges usually tells me that is the suction.

I am not seeing any bulge, but flipping it was the trick. The radiators are burning hot. I am actually gonna lower the temp and the pump as everything is too hot. Amazing and how stupid I was at the same time. I am sweating already it is so hot. I turned the boiler down to 170 and aquastat for circ down to 150. Circ is on medium and the radiators are raging hot. I can smell the heat. I am just watching the pressure to make sure it is not creeping up and found the tiniest pin leak in the threads going to to the prv. Waiting to see if it seals its self.

I appreciate all the effort and help.