How to disassemble and reassemble a water heater to paint it ?

When you want to redecorate a room, the radiator is not the easiest to paint. It must first be disassembled, painted, and finally reassembled. By following the steps, disassembling and reassembling a water radiator is not as complicated as it seems.

1 – Take the right tools

  • Provide, depending on the model of radiator, the appropriate key: Allen key, square key, adjustable spanner or pliers.
  • Prepare a large basin and old tea towels.
  • Install a tarp under the radiator to protect your floor from dirty drips.

2 – Purge and empty the radiator

You cannot disassemble the radiator without first shutting off the heating water circuit. This is to close the circuit at the boiler. It’s a little more complicated if you live in collective housing and the boiler is shared. For your painting work, you will have to wait for a period when the heating is switched off. If your work is urgent, you can always request an exceptional cut-off of the general boiler, but this will be at your expense.

As it is a closed circuit water network, the heating water must be drained after being cut off. And after emptying the water from the radiator, it will be necessary to empty the one that is in the pipes.

  • Close the water inlet tap, on the radiator heating circuit. In principle, the same tap is used to regulate the temperature.
  • Unscrew the protective cap from the adjusting teelocated at the end of the second radiator hose. Close the valve with the Allen key, counting the turns needed to close it (you will count the same number of turns to reopen it).
  • Purge the radiator. Place the basin under the purge valve and open this valve with the correct key. The purge is used to clean the radiator and expel the air, which will lower the pressure of the radiator.
  • When the pressure has gone down, it is necessary empty the water of the radiator. Place a basin under the adjustment valve (previously closed). Gently unscrew the bleed screw, between the valve and the radiator; the water flows from the radiator to the basin. If the basin is not big enough, you will have to try several times.
  • To release the radiator, fully unscrew the valve fixing nut.

3 – Remove the radiator

Once the radiator is empty, and the connector completely unscrewed (the one near the tap), you will be able to dismantle the radiator.

  • Remove the pipes from their locations.
  • Lift the radiator so as to disengage it from its wall bracket. If it is made of cast iron, bring it to several people!
  • Carefully lay it flat on the floor.
  • To prevent any leaks, temporarily close (with a collector plug or adhesive tape) the water inlet tap and the water circuit outlet.

4 – Do your paint jobs

Wait until the radiator is cold before you start painting. Clean the radiator, sand it if necessary. After applying the two coats of paint, let it dry for three days before reassembling the radiator.

5 – Reassemble and bleed the radiator

  • Put the radiator back in place on its support (or on its feet, depending on the model).
  • Tighten the nuts the return valve and the water inlet valve, with an adjustable wrench.
  • Screw it back temperature control valve and open it.
  • Open the valve water return, making the same number of turns as to close it during dismantling. Replace the tee cover (if there was one).
  • Open the bleed valve to bleed the air from the radiator. Don’t forget the basin under the drain!
  • When the radiator begins to fill, close the bleed screw. Screw it back in gently, without forcing it.
  • Close the heating circuit filling valve.
  • To make it more waterproof, add a little sealant.

6 – Check the pressure

  • After the water supply has been re-opened, leave the heating circuit run for a few minutes.
  • Check that there is no leaks when restarting the system. Run your hand over the radiator and faucets; if you feel wet traces, check the tightness of the nuts. If the leaks persist, redo the draining of the radiator and add this sealant.
  • Check the pressure of the heating circuit. On the boiler nanometer, control the number of bars. It must be between 1.5 and 1.7 bars. If the pressure is too low, open the filler valve again for a few seconds and check the pressure again.

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