no heat in one zone- all baseboards

[lapicnirp]

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

thanks
John andrews

 

[MeldrewsMate]

I'm struggling a little with your strong accent, please type slower in your replies, and try to get all the letters in place (and preferrably in the right order).

Can I assume you have an underfloor heating system?
Baseboards? Is these refering to floor temperature?

Given the above, and in a conventional underfloor system, there will be one main circulating pump either in the boiler (furnace) or close by, then another at the blending manifold (to avoid high temperatures in the floor structure).
Because you indicated that just one zone is cold the focus should be on the local circulation circuit: initially check that the pump at the blending manifold is working, this may be powered up from the local zone valve, or from another source.
Then you say the boiler only fires for a few minutes, so here the focus should be on checking the main circulating pump.

How old is the system?
Is the system water clean?
Do you have individual flow gauges to show the water flow to each underfloor zone? Is the cold one showing any flow?

 

[D_Hailsham]

'Baseboard' is what those over the pond call the skirting board!