javaboost wrote:Hello,
I'm a new HB member. I recently picked up a used VBM Domobar Super. I have a general question regarding descaling. My first try led to an over-filled boiler. Following steps from reseller to the tee but I still had water coming out of a valve on the boiler.

I believe that you either had old instructions or missed a point. The behavior you describe is normal if steps are not taken as discussed below.

The full instructions, updated, are here:
http://www.1st-line.com/cofffact/vibiemme_descaling.htm

When you removed the wire from the level sensor, the machine has no way of knowing when the boiler is full. In that state, if you turn the machine on, the pump will fill the boiler continuously. The air and water in the boiler will have no where to go and pressure will build up. The "valve" that opened on the boiler is a safety pressure relief valve that is included on all sealed boiler systems. The solution is to first open the hot water valve before turning on the machine when descaling any time the level sensor wire is disconnected. This gives the pressure an outlet so that the safety valve does not open.

javaboost wrote:Hi Jim,
Thanks for helping again and your patience. Though I felt I got the instructions correct, I obviously missed that step to create the overflow prob. I believe that I understand the nature of this subject a lot better now. That was part of the problem. I didn't understand the dynamics of it and couldn't figure out how to prevent it from continuously overflowing. I'm pretty sure I got it now so I should be okay at the end of the month when I descale again.

FYI. The microswitch swap went smoothly.

FYI, that's Randy, not Jim. Randy wrote the VBM manual for 1st-line, so maybe that's where you found confusion.

javaboost wrote:Oops. My mistake. Thanks for the correction.

No worries. Just giving credit where credit is due

kbsmith33 wrote:I, too, experienced the overflow issue when descaling my VBM. I opened the hot water valve before turning on the pump, but water still came out of both the hot water wand and the boiler pressure relief valve.

rewritten 7/2 - I was reminded by Admin that I took some things for granted in the oroginal text of my post, so I have completely rewritten it below:

Descaling agents are strong acids. If during the descaling process the pressure safety valve opens in the VBM Ds (or in most any such machine) the agent may be sprayed, under pressure, inside the machine. Even if it just dribbles, the acid creates the possibility of cause damage to metal parts over time if left in the machine (not to mention that it would be nasty if it sprayed in your eyes). The parts most likely to be damaged are the electrical connections. Other exposed metal parts can become stained or damaged as well, but these would be more cosmetic problems than functional problems.

If the user wishes to lessen or eliminate long-term problems it is best to get the aid out of the parts which were exposed. The only effective way that I know how to do this is to rinse the parts with water.
- UNPLUG MACHINE
- Allow machine to cool
- Only pure water should be used with distilled or reverse osmosis being preferred. Use a spray bottle or irrigation bottle or similar to thoroughly rinse as necessary. Do not spray directly into the control boxes or other sensitive electronic parts. It these are affected by the acid it is best to remove them for cleaning or allow a technician to deal with it.
- After thoroughly rinsing the parts, use compressed air to thoroughly blow out all traces of water.
- Leave machine open and allow to dry (at least 24 hours) before plugging it back in.

There are two possible ways to avoid this situation: The first would be to temporarily put some sort of hose or tubing on the valve in question so that if any liquid is expelled through it, the hose could carry it away from the machine. Alternatively, a rag might be used over it. Place then so that the hose does not direct acid to an unwanted area and so the rag cannot touch any electrical connections. Be sure to remove either after the job is completed.

The second way would be to follow the instructions- whenever the boiler water level's sensor wire is not connected, never run the pump without the hot water valve being fully opened to give the pressure in the boiler a place to escape. Removing the spray-head from the hot water wand, and opening the steam valve as well when the poump is run will also go a long way towards avoiding the situation.