Xylem CWM29-V3, CWM41-H3, CWM21-V3, CWM40-V3, CWM41-HT3 Installation, Operating & Safety Instructions

© Cleghorn Waring 2017

WATER STORAGE HEATERS
(CALORIFIERS)

INSTALLATION

,

OPERATING
AND SAFETY

To obtain the best performance from your C-Warm water storage heater

please read these instructions carefully.

Failure to observe the recommended

procedures may resul t in damage to equipme nt or in pe rsonal injury, and may
invalidate the supplier’s warranty.

INSTRUCTIONS

3 bar rated

Issue

B

for BOATS

Z/PWL6

DOC597/17

2

CONTENTS Page no.

Introducing your C-Warm water storage heater ............................ 3

Safety ...................................................................................................... 4

Adapting the engine cooling circuit ................................................. 5

Before you start: p re-installation checks ........................................... 6

Location ................................................................................................. 6

How to fit an auxiliary header tank if necessary ............................. 7

Fixing the heater in place ................................................................... 8

Connecting the pipework ................................................................... 10

Fitting the temperature/pressure relief valve ................................... 11

Fitting an electric immersion heater .................................................. 12

Regulating the temperature of engine-heated stored water ...... 14

Hot water expansion ............................................................................ 15

Regulating the cold water inlet pressure .......................................... 15

Using the heater ................................................................................... 16

Maintenance ........................................................................................ 16

Winter precautions ............................................................................... 16

Problem solving ..................................................................................... 17

Table of connections and fitting sizes ............................................... 18

Warranty ................................................................................................ 21

Calorifiers and Water Storage Heaters – what’s the difference?

None. ‘Calorifier’ is a word borrowed from industrial process heating, meaning a water vessel containing
a heat exchanger (such as a coiled pipe) through which steam or hot water passes, giving up its heat to
the water contained in the vessel.

3

A C-Warm water storage heater offers a
simple and convenient means of
enjoying the benefits of stored hot water
on board your vessel, at no extra cost in
fuel.

Installation is straightf orward. Provided a
few simple rules are obeyed, your
heater will give you lengthy service with
virtually no maintenance.

INDIRECT COOLED ENGINE

DIRECT COOLED ENGINE

INTRODUCING YOUR C-WARM WATER STORAGE HEATER (CALORIFIER)

C-Warm storage heaters are designed
for use with INDIRECT MARINE ENGINE
COOLING SYSTEMS using a closed loop
of hot water circulating through the
engine heat exchanger. Twin coil
models may also be used with a second
engine or with gas or diesel burners. A
mains

voltage a.c. immersion heater

can be fitted.
If an auxiliary burner is used follow the

fitting and operating instructions
supplied with it.

With water entering the coil at 82°C, a
C-Warm heater is designed to provide a
full charge of hot water at 60°C w

ithin

15 to 25 minutes. The larger heaters
have more coil turns, so heating time is
virtually independent of the volume of
water contained in the storage heater.

With DIRECT COOLED ENGINES, the
temperature of the water leaving the
engine is more variable

. For effective

use of a storage heater, the
temperature of the water entering the
coil should be at least 50°C.

Before you adapt a new engine’s
cooling circuit to take a water storage
heater, check with your engine supplier
to ensure that you do not inv

alidate the

engine’s warranty.

4

Your C-Warm water storage heater is
part of an unvented (‘closed’)
pressurised water system. Most domestic
systems in the UK are vented to
atmosphere (‘open’). In continental
Europe and elsewhere unvented
domestic systems are the normal type.

With proper protection against
overheating, unvented systems present
no hazard to the user. Safety

precautions are required by law for
unvented systems installed in houses in
the UK. The requirements are set out in
Building Regulations and local Bye-laws.
Although no such regulations exist (at
the time of printing) for unvented
systems in boats, these instructions
describe and recommend precautions
that comply with UK law for domestic
systems.

C-Warm heaters are designed for use
with clean, fresh, drinkable water. Salty
or heavily chlorinated water is more

corrosive than pure water, and the
working life of the heater and its fittings
may be shortened.

Copper is moderately resistant to
corrosion in hot sea water, so the heater
itself can be used with sea water,
though its working life may be

shortened. Because the temp/pressure
relief valve may corrode, C-Warm is not

recommended for sea water use with an
electric immersion heater.

CAN I USE A C-WARM STORAGE HEAT E R TO HEAT SEA WATE R ?

SAFETY

WATER QUALITY

● Fit a C-Warm double-protected electric immersion heater. See page 12

● The temperature/pressure relief valve supplied with your C-Warm water

storage heater MUST be fitted in the heater.

- in the event of overheating due to thermostat failure in an electric
immersion heater, the relief valve will open before the water can boil,
eliminating the risk of a sudden release of large amounts of scalding
water and steam.

- the relief valve protects the storage heater itself from excessive pressure
and possible damage caused by hot water expansion or by failure of
the pressure switch on the pump.

Some additional precautions are noted in the text. These precautions are
marked as shown:

ESSENTIAL PRECAUTIONS

5

The schematic diagram shows the installation principle. Contact your engine
supplier for advice about the recommended connection points on your engine.

INDIRECT CO OLED ENGINE

For maximum flow through the coil, the
inlet connection should be close to the
engine (A) and the discharge
connection should be close to the
circulation pump (D). Somewhat less
flow through the coil can be attained, if

required, by taking off hot water from a
point (B) downstream of (A) and
returning it to point (C) upstream of (D),
so that the pressure difference between
the coil take-off and return is a little less.

DIRECT COOLED ENGINE
Some direct-cooled engines provide for

a relatively high engine block
temperature. The recommended
connection points for the C-Warm

heating coil will vary according to the
engine design. Check your engine
manual and if necessary contact your
engine supplier for advice

ADAPTING THE ENGINE COOLING CIRCUIT

6

I. Check that you have received

the correct C-Warm heater and
accessories. Check immersion
heater power and voltage.
Report any damage or
discrepancies to your supplier
without delay.

II. Check the dimensions of the

heater and recheck the
dimensions of the space for its
installation in your boat.

III. Read through these instructions

carefully, noting additional items
required for installation.

Your C-Warm water storage heater may be located in any convenient and
accessible position subject to the following considerations:

I. With pumped cooling water

circulation, the storage heater
can be located above or below
engine level. For best circulation,
natural convection should assist
the pumped flow.

II. There must be no air locks in the

cooling water circuit. Either
locate the water storage heater
with its upper coil connection
below the engine’s water filling
point, or fit an auxiliary
header/filler tank above the
highest point in the cooling water
circuit. See page 7.

III. The longer the pipe run

between water storage heater
and engine, the more work the
engine’s cooling water
circulation pump has to do.
Minimise the reduction in water
flow rate by locating the
storage heater near the engine.

IV. Vertical C-Warm storage heaters

MUST be mounted vertically,
horizontal heaters MUST be
mounted horizontally.

BEFORE YOU START

LOCATION

7

For installations where the upper coil connection is above the level of the engine’s
water filling point.

How to fit an auxiliary header tank if necessary

1. Blank the existing header tank by

using a flat cap that does not
obstruct the overflow pipe.

2.

Fit a new expansion tank nearby, at

a height just above the top of the C­Warm water storage heater coil.
Connect it to the overflow outlet on
the original header tank, using a
suitable pressure hose (see diagram

)

The expansion tank for a car radiator

is suitable for engine cooling systems
up to about 200 litres in total volume.

3.

Fit an air bleed close to the top coil

connection of the water storage
heater. On filling the system with
water, ensure that all the air in the

cooling circuit escapes via this bleed

or from the engine.

4.

On starting the engine check for loss

of liquid and for air locks in the
extended cooling circuit.

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