Gravity Hot H20 Conversion

Bruce M

Does the sytem work properly now? If it does, leave it alone. A properly piped gravity system is a work of art with few moving parts. It is hard to perfect upon perfection.

Jonny Service

GRAVITY HOT H20 CONVERSION

HI ALL,
LOOKING AT CONVERTING AN OLD GRAVITY HOT H20 SYSTEM TO CIRCULATING H20.LOOKING FOR ADVICE ON MAYBE PRIMARY SECONDARY WITH CONDENSING BOILER.ANYONE DONE THIS?
THANKS........JK

Jim_65

The

gravity system may work well but the heat source may be lacking in overall efficiency. From my experience in gravity conversions to a mod-con replacement is generally in the 30-50% reduction in fuel consumption.

$omething to consider...

Mike T., Swampeast MO

If the system is functioning under gravity, fueled by a gas conversion burner and the homeowner is fed up with high fuel bills than your only option is a mod-con boiler.

If TRVs (thermostatic radiator valves) are installed on the radiators at the time of conversion [highly recommended] then every room will be "zoned" with potential system efficiency maximized. The Vitodens by Viessmann is a natural choice for such a system and in most cases primary/secondary will not be required. Such a system is an ideal load for the Vitodens and its integral variable speed circulator.

If you don't use TRVs, primary/secondary will be required.

Properly sized and installed, the reduction in fuel consumption will be drastic regardless of the mod-con used with 50% being quite easy to beat.

Bob Bona_4

if it

is still gravity, the boiler probably is a 80 gallon capacity or more fuel sucking monster. Why pay to heat that water up before things get moving?

Go mod/con if gas, something like a 3 pass boiler if oil. Now you have a source to make and store hot water in an indirect tank. Convert to pumping. Maybe zoning? Look in the Library for tips on getting started.

jp_2

I don't know mike,

I have a neighbor with a 3 story victorian, 1 zone, no TRV's.
house seems to heat fine.

I can easily see replacing that atmospheric boiler with any mod/con.

Mike T., Swampeast MO

Gravity Conversion

TRVs aren't required but they are they offer the only way to maintain flow rates similar to what occurred via gravity. They also allow room-by-room zoning that self-compensates for solar and occupancy gains.

Without TRVs, 20+ gpm secondary (emitter) flow is common using the well suited circulators.

Any well-sized properly installed mod/con will do well driving the gravity conversion, but TRVs allow a directly connected mod-con to thrive.

Jonny Service

GRAVITY HOT H20 CONVERSION

Thanks for all the input!Iwill be doing my homework now..........JK