Hot water zone off steam boiler

Greg_23

did you use tappings in the boiler on opposite sides, one high and one low? The water must pass across the boiler to pick up temperature or you will continue to get the cooler water across the bottom of the boiler.

Brian Harrington

hot water zone off of steam boiler

Hello,
I installed a hot water zone off of a oil fired steam boiler
I had to use the bottom tappings on the boiler. In order to
get 180 degree water to go through new zone the boiler has to run for at least an hour. By then the entire house is 80 degrees. Is there something I can do to fix this problem? Please let me know.
Thank you,
Brian Harrington

Glenn Sossin_2

Air Bound?

I am assuming this hot water loop is on the same level of the boiler - I'd say your circ is plugged up with sediment/crap or your airbound. If the baseboard is above the boiler - there is a unique arrangement of piping requiring checks, air vents that can be sealed off after filling.

You should use a bronze circ - it will last longer, along with wye strainers with a blow down drain, to filter out the crud. Also should have used an aquastat/high limit, on the line calling for heat so you don't make steam.

Sound like your heating by conduction maybe? If the pump works (not plugged/air bound), it should take a minute or for you to feel the heat coming out of the radiation. If not, hot water is not flowing.

Good luck

Unknown

How is it wired and piped?

Is it like this?

Noel

Unknown

If the zone is on the same level as the boiler you can just run the pipes directly to the baseboard from the boiler. If the zone is above the boiler,then you have to drop the pipes to the floor from the boiler before you pipe them upward. This is a thermal leg.

You also have to blend the baseboard return water with the supply water. turn both t-stats on full blast. Watch the temp gauge down stream from t-mix as both the steam & baseboard run. Adjust your mixing with a globe valve accordingly. You can also use a Tekmar 3 way mixing valve set-point contol to give you 180 degrees.

Make sure your aquastat is not set too high. Having this set too high can cause the boiler to make steam when only the baseboard zone is calling. Those controls are not the most accurate things in the world. I usually keep mine @ 160 degrees.

Make sure your baseboard load does not exceed your boilers pick up factor.
Example: 300 sq. ft. steam x 1.33 = 399
99 sq. ft. steam x 180 degrees = 17,820 BTUH
17,820 BTUH / 500 BTUH per linear ft. of baseboard = 35 total ft of baseboard.
Having too much baseboard will cause everything to take a long time to heat up, even if the boiler is idealy sized & piped.