ECR UTICA BOILERS SVB II Series, Installation, Operation & Maintenance Manual

14

1. 

Boilers may be vented horizontally as shown in 

Figure 8, Page 13

 . 

 Vent pipe is pitched 

down

 from 

boiler to vent termination. Do not connect other 

appliances to this vent.

2. 

Vent Pipe Material:
A.  UL Listed Z-Flex Z-Vent stainless steel vent pipe 

from boiler to vent termination,

 -or-

B.  UL Listed Heat-FabSaf-T-Vent stainless steel vent 

pipe from boiler to vent termination,

-or-

C.  UL Listed Flex-L StaR-34 stainless steel vent pipe 

from boiler to vent termination,

 -or-

D.  UL Listed ProTech FasNSeal stainless steel vent 

pipe from boiler to vent termination.

3. 

Clearance to Combustible Materials:  For stainless steel 

vent pipe maintain 6” minimum air space clearance to 

combustible materials.

4. 

Vent Pipe Size:
A.  2, 3, 4 and 5 section boilers use 3” vent pipe 

connected directly to the outlet of the induced draft 

blower.

B.  6 and 7 section boilers use 4” vent pipe, starting 

with a 3” to 4” stainless steel vent pipe transition 

that is connected directly to the outlet of the 

induced draft blower. Do not use 3” vent pipe on 6 

or 7 section boilers.

5. 

Vent Pipe Length:
A.  For stainless steel vent pipe, the maximum 

horizontal vent length is 30 feet plus one 90

°

 elbow 

plus termination 

fi

 tting.

B.  Minimum horizontal vent length for all vent 

materials is 2 feet plus one 90° elbow plus 

termination 

fi

 tting.

C.  For additional elbows reduce the maximum vent 

length as shown: 

• 3” - 90° elbow - reduce vent length 3 feet per 

each 3” elbow

• 4” - 90° elbow - reduce vent length 6 feet per 

each 4” elbow 

Example:

 6 section boiler has 3 elbows plus the 

termination 

fi

 tting. This means 2 additional 4” elbows will 

be used, at 6 feet per elbow. This is equivalent to 12 feet 

of pipe (2 x 6 =12), therefore maximum vent length is now 

18 feet (30 -12 =18).

6. 

Vent Termination Fitting: For all vent pipe materials, 

you may use either:
A.  A 90° elbow pointing down, 

fi

 tted with a minimum 

1/4” mesh screen to keep out rodents and birds. 

The elbow shall be of the same material and size 

as vent pipe. The elbow exit should be at least 6” 

away from exterior wall as shown in 

Figure 8

.

 -or-

B.  Tjernlund VH-1 Series side wall vent hood. For 2, 

3, 4, 5 section boilers use VH-1-3”, For 6, 7 section 

boilers use VH-1-4”.

7. 

Vent Pipe Termination Location See  Figure 9 :
A.   When venting through combustible walls, 

combustible clearances must be considered. The 

VH-1 Side wall vent hood provides both the outside 

vent termination and a double wall pipe for passing 

through a combustible wall up to 8” thick (VH-

1-4”) or 9” thick (VH-1-3”). The hole in the wall 

must be 6¼” square for 3” vent pipe and 7 1/2” 

square for 4” vent pipe, in order to insert the VH-1 

side wall vent hood. The VH-1 may also be used in 

noncombustible walls.

B.  If the 90° elbow is the termination 

fi

 tting of choice, 

then the single wall pipe will be passing through 

the side wall. For combustible walls, a UL listed 

thimble shall be used where the single wall pipe 

passes through the wall. For combustible walls 

using Z-Vent, Saf-T-Vent, or StaR-34 vent pipe, 

use the following:

• 3” vent pipe - use Simpson’s Duravent 3” thimble 
• 4” vent pipe - use Simpson’s Duravent 4” thimble. 

Maximum wall thickness with this thimble is 7 

inches.

For combustible walls using ProTech FasNSeal where the 

single wall vent pipe must pass through the side wall, a UL 

Listed FasNSeal wall thimble shall be used. 
The thimble is adjustable for different wall thickness, with a 

maximum wall thickness of 7 inches. Seal the thimble along 

the outside edge of the plate with caulk or silicone and 

fasten to the wall with screws or nails.

C.  For single wall pipe through non-combustible 

walls, the hole through the wall need only be large 

enough to maintain the pitch of the vent pipe, and 

provide proper sealing. A thimble is not required 

for single wall pipe passing through noncombustible 

walls.

HORIZONTAL VENTING INSTRUCTIONS