Boiler won't fire

[ryandebny]

I have a hot water boiler. When I turn it on I hear the pumps click on but the boiler won't fire.
The pilot light is on.

[SeattlePioneer]

You probably have a "hot" boiler system. In such a system the boiler water is kept hot all the time, and the thermostat turns on the pump which circulates water (and thus heat) to the radiators. In such systems, an operating aquastat turns on the boiler to keep the water hot. Often there are two or even more aquastats. One aquastat (usually set at 140-160 degrees) keeps the water hot to that specified temperature, and the other aquastats (set at 180-210 degrees, a higher temperature) act as limits to shut off the burner if things get excessively hot). You need to identify the operating aquastat. Do you have a multimeter that will measure AC voltages and understand how to use it?

[paul52446m]

Boiler won't fire

I have a hot water boiler. When I turn it on I hear the pumps click on but the boiler won't fire.
The pilot light is on.

As said in the last message very few boilers are wired to maintain temp.
The aquastat's are there to control the water temp when the boiler is on calling for heat.
Start with checking fuses and 120 volt power to the boiler. If you have 120 volt power then you have to check for 24 volt power. Your gas valve would be 24 volt.
Do you have zone valves? If so is the thermostat operating and opening the zone valve, The end switch in the zone valve is what makes the burner relay.
Are you zone valves powered by a separate transformer?
Your aquastat's could be powered through the 120 power or through the 24 volt power. It would really help if i could see pic. of the controls and the wiring diagram. Paul

[jamesborn]

aquastat

You probably have a "hot" boiler system. In such a system the boiler water is kept hot all the time, and the thermostat turns on the pump which circulates water (and thus heat) to the radiators. In such systems, an operating aquastat turns on the boiler to keep the water hot. Often there are two or even more aquastats. One aquastat (usually set at 140-160 degrees) keeps the water hot to that specified temperature, and the other aquastats (set at 180-210 degrees, a higher temperature) act as limits to shut off the burner if things get excessively hot). You need to identify the operating aquastat. Do you have a multimeter that will measure AC voltages and understand how to use it?

which aquastat can I you use in this case? Honeywell L4006A2007, Honeywell L4006B1163 I can choose please help me with it. I found it at pexuniverse.com /honeywell-aquastats

[DuneMe]

The Aquastat appears to be a High / Low Temperature unit.

Also, it appears that it will have a 24v signal.

Hope this helps.

L4006A2007 - Honeywell L4006A2007 - High or Low Limit Aquastat, 100-240°F range, 5-30°F Adj Differential

[DuneMe]

Looking here . . .
Hydronic Controls by HONEYWELL - Aquastat Relays by Zoro Tools Industrial Supplies
It looks like it might be 12v???

Millvolt025A @ 025 To 12 Vdc

[HayZee518]

(It looks like it might be 12v???)
how do you know? you're just guessing.

[DuneMe]

Isn't this the signal voltage???

Millvolt
025 A @ 025 To 12 Vdc

[HayZee518]

nobody said ANYTHING about a millivolt system. YOU said it when you were browsing the web and pulling stock numbers out of thin air!

[DuneMe]

I'm ok to be wrong (happens all the time) just tell the OP what the voltage is. . . That IS all that matters now, not weather or not i was wrong???

[DuneMe]

Just for future reference, when someone uses three question marks, they aren't sure about it. "???"

I even said "might" below. . .

Looking here . . .
Hydronic Controls by HONEYWELL - Aquastat Relays by Zoro Tools Industrial Supplies
It looks like it might be 12v???

Millvolt025A @ 025 To 12 Vdc

[HayZee518]

I'm not telling the OP anything. He's looking to US for help! He said the system is 24 volt control. There was no mention of a millivolt signal until YOU brought it up The problem is the aquastat and the boiler not firing. the high limits and the aquastat(s) feed the burner relay, the PROTEC-OR-RELAY. I take it you are very familiar with the Honeywell Burner control/ I mean being an X BOILER MAN. This ought to be second nature to you.
C'mon "EXPERT" give us your thoughts!

[DuneMe]

Thank you. . . That is the kind of answer(s) I think will help the OP.

[paul52446m]

Looking here . . .
Hydronic Controls by HONEYWELL - Aquastat Relays by Zoro Tools Industrial Supplies
It looks like it might be 12v???

Millvolt025A @ 025 To 12 Vdc

Most Aqua stat's can be used different ways. Some of them have different temp. setting so it depends on what we are using them for. That would be my first question, what do you want the Aqua stat to do? What are you using it for?. Most all Aqua stat's have a set of points in them so you can use them of Cir. pumps on 120volt power Or the can be used for 24 volt, or milivolt power. Don't remember seeing and 12 volt system out there.
Anyway both these post are about a month old so i don't think the guys will be getting back with us. Especially if they read all this arguing Paul