16
TUDOR NHRE
18.6 secondary
circulation
It is recommended that long dead legs are avoided and that a secondary circulation system is installed
as shown in figures 1 - 4.
18.7 anti stratification
system
Where there is no, or poor secondary circulation it is highly recommended to install an anti-
stratification link utilising all components as would be installed in a secondary circulation system. This avoids
high temperature water from being generated at the top of the appliance under light load operating
conditions. Failure to properly prevent stratification may cause nuisance operation of the safety high
temperature cut out thermostat.
typical anti-stratification system
Drain Cock
IV
IV
NRV
Temperature
& Pressure
Relief Valve
Isolation Valve
Small
Bronze
Pump
HW
Draw offs
fig.8
If the installation is unvented then the following information regarding system water capacity is of the
utmost importance. If the specific installation has a water capacity greater than can be accommodated by
this (standard) expansion vessel supplied with the water heater, then additional expansion vessels must be
installed. Contact MHS Boilers Ltd for advice and guidance on selection of additional expansion vessel/s.
Water Heater Model
NHRE 18
NHRE 26
NHRE 36
NHRE 60
NHRE 90
Standard Expansion
Vessel Size
25 litre
25 litre
40 litre
40 litre
40 litre
Max allowable system
content with standard
expansion vessel
315 litre
315 litre
500 litre
500 litre
500 litre
Max allowable pipework
length with standard
expansion vessel
245m of 28mm Tube
75m of 28mm Tube
424m of 28mm Tube
283m of 28mm Tube
252m of 35mm Tube
Summary of Contents for TUDOR NHRE 18
Page 27: ...26 TUDOR NHRE 28 0 parts list...
