Marstair 526 HL Series, Technical Manual, Page: 29 / 31

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LOW PRESSURE HOT WATER COIL KIT
This kit provides LPHW heating for HL (526) and HLR (527) indoor units.
A control valve is not provided in this kit.
Since the coil is upstream of the evaporator, a de-ice thermostat is not necessary on the LPHW coil. It is, however, highly
recommended to fit a de-ice thermostat to the evaporator to protect the LPHW coil.
UNIT SIZE KIT PART NUMBER Item Qty Description
HL/HLR 380 52600227 1 1 LPHW coil assembly
HL/HLR 460 52600226 2 7 Grommet strip
HL/HLR 540 52600224
Fitting the LPHW coil is best done prior to installing the unit.
1 Remove the unit cabinet and lay the unit on its backpanel.
2 Remove the three No. 10 electrics tray retaining screws and spring the tray free.
3 Remove the four No. 10 evaporator coil retaining screws and lift the coil away complete with sealing plates and the
insulation plate.
4 Remove and discard the blanking plate from the left hand hanger bracket.
5 Remove the tape covering the slots in the right hand hanger bracket and fit the grommet strips in place, (Fig. 1).
6 Position the end of the LPHW coil into these slots and secure the left hand end plate to the left hand hanger bracket,
(Fig. 2).
Fig. 1. Fig. 2.
7 Replace the evaporator assembly and electrics plate.
8 If a valve is to be fitted, connect to the indoor unit as shown in either Fig. 3, (HL) or Fig. 4, (HLR).
Fig. 3 526 Models Fig. 4 527 Models.