Preventing Excessive Flue Gas Temperatures; Standard Values For Water Quality; Flow Temperatures ≤ 100 °C (Vdi 2035 Part 1-2) - Viessmann Vitomax LW Operating And Service Instructions

Information on maintenance

Preventing excessive flue gas temperatures

Excessively high flue gas temperatures make the
system less efficient
Cause of fault Remedy
Altered burner Adjust the burner correctly
setting
Contaminated Clean the boiler system
boiler system
Tab. 4

Standard values for water quality

Advantages of complying with the guidelines
■ Prolonged boiler service life
■ Reduced repair costs
Advantages of using chemical water treatment
■ The specified standard values and water conditions
are observed
No additional corrosion protection is required
■
– if the system is designed as a hot water heating
system sealed against corrosion and
– if all the other instructions stated in the "Standard
values for water quality" chapter are complied with
Flow temperatures 100 °C (VDI 2035 Part 1-2)
≤
Recommendations
Prevent scale deposits (calcium carbonate) from
■
forming on the heating surfaces.
■ Pay particular attention to the standard values speci-
fied in VDI Guideline 2035 Part 1 "Prevention of
damage in water heating installations - Scale forma-
tion in domestic hot water supply installations and
water heating installations"
Conditions of applicability
■ Fill and top-up water consumed by the system during
its service life: max. 3 times its capacity
■ Specific system volume: < 20 l/kW heating output.
For multi boiler systems: The output of the smallest
steam boiler or hot water boiler applies here
■ All measures to prevent water side corrosion in
accordance with VDI 2035 Part 2 have been com-
plied with
Standard values (extract)
Total heating output
Total alkaline earths
Total hardness
Tab. 5
All manuals and user guides at all-guides.com
(cont.)
kW 600
>
3 < 0.02
mol/m
°dH < 0.11
Recommendation
Continuous monitoring of the flue gas temperature
using a flue gas thermometer
Recommendation
Use chemical water treatment in the boiler system.
Request a quotation from Viessmann (for contact
details see page 32).
Note
Observation of the following requirements is a neces-
sary condition for safeguarding your warranty rights.
The warranty excludes damage caused by scaling or
failure to adhere to water quality conditions.
Fill and top-up water
Soften the water:
■ If the total of alkaline earths in the fill and top-up
water exceeds the standard value
■ If larger fill and top-up water volumes are expected
Log the water volumes:
Install a water meter
■
■ Enter the volume of water filled and the water hard-
ness into the system operator's log
Reduction of water consumption:
Install shut-off valves in each section of the system.
This enables the heating water to be drained just
from the affected section when work is required on
the system.
Operating information
Start the system in stages:
■
Begin with the boiler with the smallest output
–
■ Prevent localised limescale deposits on the heating
surfaces by setting a high heating water flow velocity
■ When carrying out work on the system, only drain
the affected sections of the system
Operating information
11