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Here is my guide on how to remove a Malaga 3 water heater, and remove and replace the burner and/or ignitor/flame sensor.

There are some dangerous bits, as you will need to work with gas, water, 12v and 240v wires.  Nothing too scary, but do so at your own risk.  These instructions are written by me for me for future use, and anyone using them apart from me accepts the fact it is their choice and they accept all risks.  I am an IT expert who is handy with a toolbox, so don’t mix me up with a gas/electrical certified person!   Suggest you read the entire article before thinking of doing anything.

My fault

On gas, I kept getting the “6 flash” error code which means “no gas” or “no flame” or something similar.  The usual fixes or things to check are:-

1 – Is the gas on?

2 – Is there 12v supply, and is it >10v?  (If its low voltage the solenoid may not open)

3 – Is there a good earth

Also, on mine, you could tell (from outside) that there was gas, and it was lighting, it just wasn’t staying lit.  This suggested the electronics could not detect that there was flame.  The ignition system is also used to detect if the flame is lit, so a simple single wire.  These can fail over time.

Support

Propex support were superb, answering phone quickly and answering queries quickly, and also sending a spare part (at reasonable cost) to me in France (to the local post office for me to collect).  Always try these guys first – 10/10 for after-sales service. +442380528555. 

 Tools Reqired

  • Mole grips
  • Phillips driver
  • 7mm socket (for jubilee clips)
  • 15mm spanner (x2 – or x1 + 1 adjustable)
  • Long nose pliers (for making crimp)
  • 13mm spanner
  • Pozi-drive driver (no idea of size)
  • Sand paper/wire brush/scraper for rust removal

NOTE:  My fuse on board the heater also failed during this work, I think it was more down to the heater being tossed around whilst being worked on rather than a real blow.  Fortunately I carry spares, its a 1A clear surge protect fuse.

 

Simple preparation

1 – Turn off gas stop cock to heater!

2 – Turn heater on (on gas) – which will fail, but it will flush/release the gas pressure to the outside.  Once it fails (1 minute) – turn heater off.

3 – Turn off water pump

4 – Open a hot tap, and leave open

5 – Open drain valve on boiler

6 – Isolate 240v mains (if on hookup) – Even consider disconnecting all 240v.

After 5 mins or so the boiler should empty and all the water pressure released.

Remove cover

Remove 2x Phillips screws and remove front cover.  Don’t get scared!

Disconnect stuff

I have marked each connection on my photos for you.

1 – take a photo of the wiring – you may need it to put stuff back!

2 – Disconnenect mains earth, live (brown) and neutral (blue) from the board – push on/pull off spade connectors

3 – Disconnect 12v feed to board (squeeze and pull)

4 – Disconnect control panel (squeeze and pull)

5 – Disconnect cold feed and hot output pipes, and if you have a spare connector, join the 2 together so water can still work without the boiler in place

6  – Disconnect gas feed.  This is “normal thread” and I used a 15mm spanner to turn, and a spanner to “hold” the pipe in place to prevent twisting.

7 – Close drain valve, and pull pipe up and free

Make sure all wires are safely stowed.

Unbolt from mountings

This will be unique to you, so just find where it is mounted.  I simply had 2 screws holding it in.  For ease of refitting, I marked the location of the unit with insulation tape.

Removing Unit

Remember the heater has exhaust pipe and intake through an external moulding, so you have to slide the unit back away from the wall where it is installed before lifting up.

Once lifting up expect a few drips of water, but it should be empty, and simply put on something sturdy to work on.

 

Removing Burner

You need to remove the burner to change the burner or the ignitor

1 – disconnect ignitor cable from board (pull/push spade)

2 – unscew 4x scews.  NOTE:  These are liable to be very tight and rusted on the inside.  Make sure you have a PERFECT fit pozi-drive head (I used one from socket set).  I still needed a mole-wrench and a lot of weight to turn.  Maybe soak in WD40 first,

3 – If you have sealant around the area, clear this off

4 – Undo nut holding has pipe

5 – Pull burner out (remember it is long!) – and also remember if you have sealant that this will be holding it in place.  Be wary of the gasket as you will need to reuse this.

 

Replace ignitor

Simply remove wire through PVC tube, and unscrew the screw holding it on.  When you reassemble, clear as much rust as possible from he ignitor mount as a good electrical contact is required.  Push new wire through the tubing, remove the end plastic and crimp on the connector spade.  Check there is connectivity from the ignitor housing bracket to the external burner plate.

My old ignitor had NO connectivity from bracket to the external plate, but after cleaning the rust and fitting the new igntor I did.  Also remember you need good connectivity between the external plate to the mains earth near the ignitor plug on the board.  You only get this when the gas feed pipe to the burner is connected.

POSSIBLY – cleaning rust etc and making sure continuity was there, as well as giving it a good clean, may have made the existing ignitor work again without the need to replace.

 

Replace burner

Simples!

Reassembly

Reassembly is the reverse of taking apart taking note of the following

1 – Make sure gas connections are tight. But not over tight.

2 – Make sure the burner gasket is a tight fit, and use sealant if unsure.

3 – Make sure the ignitor cable and cover are properly sealed in their grommet

4 – Pressure test the gas reconnections, and test joins with soapy water (gaslow pressure gage excellent for this – just make sure nothing else like fridge is on gas!).  NOTE: The burner connection cannot be tested in some installs as it is hidden away – so make sure this is tight, and do a sniff test at the very least.

5 – Make sure all connections go back in the right place!!

Putting unit back together

1 – Make sure ignitor is set up correctly, pipe/wire is through grommet okay

2 – Push burner into chamber taking care of the gasket.  Put in all 4 screws loosely, then put sealant around the edge.

3 – Tighten up the screws slowly and opposite until tight, and wipe off any oozed sealant

4 – connect gas feed pipe and tighten up

5 – connect 12v ignitor cable back to board

Putting unit in situ

1 – Put unit back into position taking note of the markings you left earlier, and scew down.

2 – Pull all wires through a convenient place which matches with the holes in the cover.

3 – Put water drain pipe back through hole in floor.

4 – connect gas pipe – use 2 spanners to prevent pipe twist

5 – connect mains earth, live an neutral in the right places

6 – connect control panel feed

7 – connect 12v power feed

8 – connect cold and hot water pipes (maybe add some sealant if needed)

Comissioning

1 – Turn pump on and open hot tap until water comes out of tap, then turn tap off.  Check pipework for leaks.

2 – Turn gas stop cock on and pressure test (if you have gaslow pressure gage, turn off all gas appliances and turn gas off at bottle.  Pressure should remain in green.  If it goes to yellow/red within 10 mins you have a minor leak (did you check before doing this job?)  If it goes down in <2mins you have a big leak.  Fix and retest

3 – Turn on heater on 12v gas only.  Does it light and stay lit?  If so great, if not you’ve got bigger problems!  (consider new PCB or burner?)

4 – Turn mains on and test

 

Finally

1 – have a beer

2 – have a well deserved hot shower at last.

3 – Buy loads of stuff from my Amazon links if you found this useful :)