LOOKING FOR POSS CAUSE OF ZONE PROBLEM

CMCPHERSON

We have a 20+ year old Slant-Fin sealed low-pressure boiler w/3 zones. Third zone (farthest from the boiler) is not getting warm enough. We've replaced the thermostat but no matter how high we set it...never warmer than 68 at the thermostat which means 60-62 degrees in all the bedrooms. Any ideas on likely cause? other 2 zones seem OK. Pressure is 10 psi and temp is 200 F. Return line is still very warm.

Been in the house 3 years and never had this problem. Actually upgraded windows in the whole house this summer so heat loss should be less than in years past. We haven't had to touch the boiler except to replace the thermocouple earlier in the season.

-Cold in Minnesota

Mark Hunt

Likely cause


It's colder than what the system was designed for.


Mark H

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Floyd_5

circ. pumps....

or zone valves???

Al Nardizzi

When temps dropped to the single digits,had similar problem. Someone on this board suggested two possible problem areas...resetting heat anticipator on thermostsat seemed to correct the problem.

hr

You may need

to increase the supply temperatures. Hotter water carries more btu's Or add a reset control that would constantly monitor indoor and outdoor temperatures and adjust accordingly.

Extreme cold, and a dash (or more) of wind will really rip the heat from a building

hot rod

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andy_5

I'd try adding a little more water to the system.If the zone is on the second floor,you need at least 15# of pressure to get the water up that high.Could also be a problem with air in the loop.But 10# doesn't really seem like enough pressure to me.

clammy

cold in 1 zone

I recently had a few service calls with the same complante.It seemed no one else noticed that the home owner had had new carpet installed with extra thick padding on there slab the carpet guys did a nice job.In fact they even tucked the padding and carpet under the baseboard leaving them with a 1/2 air gap from the covers .The baseboard was hot but no room for convection air currents to circulate heat .The homeowner did not believe me after a walk around the home and all the rooms without carpet she believed it a little bit i advised her to have all the basebord raise she didn,t like that idea so there stuck with new carpet and a cold rooms sometimes you have to be a dectective and look around

GEO_3

Check the anticipator in the new thermostat. It has to match the amp draw of what it's operating, IE gas valve, relay, zone valve. Also in this extreme weather the limit might have to go up. Increasing the high limit from 180 to 200 allmost doubles the output of fin-tube baseboard.

Mark Wolff

Here's the latest internet crapshoot!

The house wasn't designed for that cold weather. With your system temperature already at 200* the only options to wait for warm weather and install more baseboard and/or insulate the baseboard pipes in the crawlspaces and everywhere exposed and insulate your crawlspace and floor better.

Mark Wolff

LOL!

anticipators won't cause these problems. Also the boiler temp is already at 200*. Much higher and the residual heat after the high limit shuts the boiler down will kick it up to boiling.

rob

BTDT....Great service tip....

> I recently had a few service calls with the same

> complante.It seemed no one else noticed that the

> home owner had had new carpet installed with

> extra thick padding on there slab the carpet guys

> did a nice job.In fact they even tucked the

> padding and carpet under the baseboard leaving

> them with a 1/2 air gap from the covers .The

> baseboard was hot but no room for convection air

> currents to circulate heat .The homeowner did not

> believe me after a walk around the home and all

> the rooms without carpet she believed it a little

> bit i advised her to have all the basebord raise

> she didn,t like that idea so there stuck with new

> carpet and a cold rooms sometimes you have to be

> a dectective and look around



Thank-you!

rob

Great service tip....

BTDT. Thank-you for the tip!