Replacing a Water Heater in a Caravan Holiday home

Replacing a Water Heater in a Caravan Holiday home

Many customers wish to replace an existing water heater in their caravan with a new one. The possible options are as follows:

  1. Replace a Morco water heater with the same Morco model
  2. Replace an obsolete room sealed Morco water heater with a current model
  3. Upgrade an open flued Morco water heater to a room sealed model
  4. Replace another brand of water heater with a current Morco model
  5. Upgrade any water heater to a combination boiler

1. Replace a Morco water heater with the same Morco model

The only models Morco currently supply are the EUP11RS and an EUP11RSVERT. Replacing one of these like for like does not necessarily require the purchase of a new flue or fitting kit, although it is good practice to replace the fitting kit. If the installer is concerned about the condition or serviceability of the flue or fittings then they should be replaced. If any other Morco appliance is being replaced, please see section 2 for replacing a room sealed appliance, or section 3 for replacing an open flued appliance.

2. Replace an obsolete room sealed Morco water heater with a current model

A new fitting kit will be required in all instances when replacing an obsolete model. Below are the obsolete room sealed appliances with the current replacement models and the corresponding fluing options:

Obsolete Water Heater Equivalent Replacement Water Heater Flue Type Replacement Flue Option1 Replacement Flue Option 2
F11E EUP11RS or EUP11RSVERT Fan/Room Sealed RSF503 – Horizontal Flue RSF045 – Vertical Flue
F11EL EUP11RS or EUP11RSVERT Fan/Room Sealed RSF503 – Horizontal Flue RSF045 – Vertical Flue

The only material difference between the installation of obsolete and current models is the change in flue from the F11E or the F11EL to an EUP11RS where it is being flued horizontally – an RSF503 will be required for all installations. The vertical flues are the same on the F11E, F11EL and the EUP11RSVERT so may be reused if it is in good working order.

If you wish to replace one of the open flued heaters with a Morco water heater the only option is to upgrade to a room sealed alternative. This will not be a direct replacement, please see section 3 for details on upgrading.

3. Upgrade a Morco water heater to a higher specification current Morco model.

If you have any of the below open flued water heaters, you may wish to replace it with an EUP11RS or an EUP11RSVERT:

  • D51B
  • D61B
  • D61E
  • MP6
  • EUP6
  • G101
  • G111E
  • G11E
  • MP11
  • EUP11

If you plan to change from any open flued model to an EUP11RS or EUP11RSVERT then the following issues need to be taken into account::

  • The EUP11RS/EUP11RSVERT is more powerful than the smaller models and will require the gas pipe, gas cylinder and gas regulator to be sufficiently large to cope with the extra power. Your Gas Safe engineer will be able to advise you but generally the specification should be as below:
    • Gas pipe - 22mm copper from the end of the bottle rubber hose to within 3m of the water heater and 15mm copper for the remaining 3m
    • Gas cylinder - at least 19kg propane. If other gas appliances use the bottle, then a 47kg bottle should be used
    • Regulator - a 3.5kg per hour regulator is recommended
  • The EUP11RS/EUP11RSVERT will require a new flue and a new fitting kit as they are of a different size and type to the open flued heaters
  • The EUP11RS/EUP11RSVERT requires a 240V mains electricity supply so a 3-pin socket will need to be placed near to the boiler
  • The EUP11RS/EUP11RSVERT require an earth for flame recognition. If fitting off grid you will need to consult an electrician
  • The EUP11RS/EUP11RSVERT has no pilot light as it has electronic ignition
  • Fan flued appliances can use a vertical or horizontal flue – in this case the EUP11RS for horizontal flues and the EUP11RSVERT for vertical flues. As all open flued water heaters are vertically flued then the use of a horizontal flue will require the existing roof hole to be made water tight. To install a horizontal flue, it is best for the water heater to be mounted on or close to an external wall. The standard horizontal flue is 600mm long (RSF503) and we also supply an aluminium external flue collar for use with a horizontal flue (RSF060) – see photos below. The vertical flue is 600mm long (RSF045) and can be fitted with roof plates – see details and photos below. 1000mm extensions (RSF041) are available for use with either. If you need extensions, please ask your Gas Safe engineer to call Morco for advice
  • The white portion of the horizontal flue can be cut down to a minimum length of 235mm to ensure the flue projects from the external wall a suitable distance
  • The white portion of the vertical flue can also be cut down, as required

EUP11RS Room Sealed/Fan Flued Water Heater Flue Kits

RSF503 Horizontal Flue Kit RSF060 External Flue Collar

If you wish to use a vertical flue and hence utilise the existing hole in the roof then the existing flue components will need to be removed and replaced with a roof plate. We supply a 14 degree roof plate (RSF050, see photo below) or a 5 degree roof plate for use with older bow string caravan roofs (RSF051, see photo below). The roof plate fits to the outside of the roof and to maintain water tightness we suggest a good deal of sealant and some screws are used. The vertical flue is dropped in from the outside and the bottom of the black tube MUST reach the flange on the roof plate. The long white section of the vertical flue can be cut down to within 100mm of the black tube to ensure the flue mates with the flue adapter correctly. The black tube CANNOT be cut down. If the boiler is being fitted where a flue extension is required then use an RSF041 1000mm extension and cut it to fit accordingly.

RSF045 Vertical Flue RSF050 14-degree Roof Plate RSF051 5-degree Roof Plate

4. Replace another brand of water heater with a current Morco model

There are many similarities between brands of water heaters that make the replacement of one with another much simpler than it may seem.

All instantaneous gas water heaters require the following connections:

  • Propane gas supply
  • Cold water supply
  • Hot water outlet
  • Mains electricity - only for fan flued/room sealed heaters such as the EUP11RS/EUP11RSVERT

In all cases a new flue, either horizontal or vertical, and fitting kit (PKE) would be required.

As Morco only supply room sealed appliances, replacing an existing room sealed one should be simpler than replacing an open flued one, however, a Gas Safe engineer will find the installation straightforward for both types of water heater.

5. Upgrade any water heater to a combination boiler

It is possible to replace any water heater with a combination boiler in order to provide central heating in addition to instantaneous hot water. This is a simpler operation than it may seem but will still need to be carried out by a Gas Safe engineer. Morco offer a central heating kit design service. If you provide us with the following information, we will provide a quote for a kit that has all the components necessary for a full system:

  • The number and size of the radiators or towel rails required
  • The type of flue - horizontal or vertical
  • The position of the boiler in the holiday home (this may determine if a flue extension is needed).

The kit will include all pipes, pipe fittings, pipe insulation, radiators, towel rails, TRV radiator valves, combination boiler and flue. Please  click here for more information.

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