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jandrews 02-26-2013 12:40 AM

no heat in one zone- all baseboards
Hi there

I have a burnham seriese 2 model 204NCL LEI223 CGA 4.9.1969 boiler.

Problems: No heat out of one zone- all baseboards cold

So far
Checked thermostats- all work and valves make noise when turned up, switches in each zone make contact.
Took head of and verified that valve body turns loosely.

Gauge reads 192 degreess and at 18 psi

Question: when thermostat calls for heat and switch makes contact, how long does furnace remain on. When calling for heat it
only stayed on for a few minutes- 5 minutes. Is this normal?

Question: recirculation pump- comes on approximately every two - three minutes and stays on for 8 seconds, cycles through again

Is this normal?

4 zone system

one upstairs- 3 bedrooms
one upstairs- living room and dining room

one downstairs- west
one downstairs- east

all eat baseboards cold ( checked with infrared )

Question: if all thermostats are on shouldn't the furnace burners be on for quite a while until all pipes heat up?

Question: If i close all thermostats, and turn one one, how soon will it call for heat ( i.e. ) should the burners fire up
and stay on until temperature is reached.

Main Problem: east downstairs, pipe is cold above zone valve, all baseboards are cold?

I have included a diagram, if i need to shut down boiler in order to get water into it or reset system could you show me using hte diagram how i would do that

John andrews

beenthere 02-26-2013 04:40 AM

Sounds lie you have air in the system that needs to be purged or bled out. Circ should stay running as long as any zone is calling for heat. The boiler on time will vary with the amount of system water coming back to it.

how 02-26-2013 03:34 PM

The water is not circulating for some reason. the Water temp should stay below 180F max.
An air lock is the most likely cause for that one zone not operating.
Do your baseboards have bleed valves to test for or release excess air?

The pump should stay on while there is a call for heat. An eight second "on" time for the pump is an overheating motor and that might be your bigger problem.

747 02-26-2013 08:31 PM

Go to baseboard in zone not working. Pop off access cover on both ends. Do you see a bleeder. If yes you will probably need a skate key. Shut boiler off open and bleed all baseboard in effect zone.

techpappy 02-26-2013 10:11 PM

Also..the circ pump may be overheating due to dead heading against air lock..same as if you actually closed a valve..causes over heating as no flow through pump and heat builds up..clear the air lock and you should be good to go.

jandrews 02-26-2013 11:37 PM

no heet
6 Attachment(s)
Thank you so much for the replies.
I checked the system again. All zone valves operational. Thermostats work.
Not sure if call to heat for each zone valve works. Tried each separately. Turned off all thermostats and then turned each one up individually but i suspect temperature wasnt low enough for call for heat hence burner to fire up. Furnace did fire up though with one of the thermostats had been shut off for a while and the pipes in that zone were cooler.

Still have the problem with one zone. Temperature to zone valve and from zone valve is good about 110 degrees. when i went to each baseboard to bleed, found baseboards and pipes leading to them at 56 degrees. There are three baseboards in the bedroom. Left one had a bleeder, bled it , small amount of air came out then water shut if off. the other two in the far corner and could not find a bleeder on either side.

The pipes leading to the baseboards all head downward. A bit odd as this is a basement floor, cement slab. I thought they would run up and into the walls but it appears they are in the cement. I did not shut boiler off to bleed. I will try it again with boiler off.

as for the circ pump, there is only one just to the left of the boiler. Again listened and watched. It would come on for a few seconds about every three minutes regardless if there was a call for heat.

I have included photos. I am not sure how to purge the zone line. Photo 1 is my crude drawing. Photo 3 is the circ pump. photo4 shows the valves- not sure which one to close to purge. photo6 is the complete boiler and pip system.

thanks for any help..

how 02-27-2013 12:47 AM

If the 3 other zones are heating, they are not air locked and the pump would normally continue to run as long as there was a continuous calling for heat through them. If the pump continues to short cycle while any of the working zones are getting a call for heat, then you have a motor difficulty.

747 02-27-2013 01:30 AM

I'm thinking circulator pump. Its a b&g 100 series like i have. The circulator pump should stay on. Unless water temp drops really low. Then once temp comes back up it will turn back on and STAY ON. If this is the culprit the good news is this. The motor only can be replaced. Only 3 tools required. Phillips head screwdriver to take off cap concealing wires. Wrench. There are four bolts on front of motor assembly two top two bottom. Finally allen wrech to disconnect coupler on motor shaft which is a 118706 coupler.

Or its the zone flow valve on non heating zone needs replaced.

Finally you have a very straightforward system. A plumber who works on boilers would NOT charge big money to fix.

techpappy 02-27-2013 08:47 AM

Check for voltage to pump. If voltage is intermittent then it could be the Aquastat pump control. Not likely but, easiest to check for voltage first. If you have to remove pump..turn off breaker for boiler, shut off all supply and return valves to isolate system, if they are available, otherwise you will have to drain system before you remove pump...If you have a supply and return valve at ther boiler that would do it. Crack open Pressure Relief Valve to allow air in for faster draining. If you can hook up a garden hose to the drain from a nearby water source then it is preferred to refill the boiler that way with the relif valve open untill water comes out otherwise just open Automatic feedwater valve and crack open isolation valves at boiler to allow system to fill. You will then have to bleed the system. It is best to just open bleed valve at highest point in system for the air to escape.

TheBobmanNH 02-27-2013 08:56 AM

Don't get caught up in the boiler firing up either. It's the pump you're worried about. The boiler only fires up if the water temperature drops, it doesn't matter who calls for heat. it's something in the pump / valves / circulation.

techpappy 02-27-2013 09:15 AM

ALSO...take the cap off the air vent located just above boiler then depress the valve needle to allow any air to escape...air can gather at top of boiler and prevent proper circulation AND can affect the temperature aquastat/controller as well.

747 02-27-2013 09:01 PM

On the b&g 100 series pump. He doesn't have to worry about water when dropping just the motor assembly. There are 4 bolts which hold it on the bearing assembly NOW if he was dropping the bearing assembly you have to drain system down water will come.

danpik 02-28-2013 12:20 PM

I may have missed it so I will ask...Does the pump short cycle when the three good zones call for heat? Or is it just short cycleing when the cold zone calls for heat?

Also, Did this just start suddenly?

Are all of the valves associated with the cold zone open?

There are, on most systems, isolation valves that can be closed to shut off a zone. Unfortunatly, they do not turn off the power to the zone valve when they are closed.

jandrews 03-04-2013 10:40 PM

Thank you
Thank you to everyone who gave me insight to my problem. All problems have been fixed. It was a number of issues namely air lock and failure of pump.

I lowerd the pressure, installed the pump, then brought the pressure up while getting the air out of each zone.

It was mainly the pump. Did not know what it sounds like or how it should be working as the pump was shot. Coupler jammed, broken spring. Bought a new complete pump for $ 257.00. This b and g requires oiling which had never been done. I will buy new coupler for $ 12.00 rebuild with new seals and keep it as a spare.

Once i installed the new pump my problems were solved. The pump runs with a quiet humm ( never heard the humm before and the coupler spins when the furnace kicks in and continues running until heat is distributed.

Everything works perfectly now. Thanks again.


techpappy 03-04-2013 10:53 PM

YAAAAYYYYY!!!!!!!.. Good to hear you got the issues resolved!:thumbup:

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