Flushing Vaillant ecotec 831 combi boiler

Hi there,

I would like to flush my heating system with sentinel x400 for a day or so then drain till clear then finally fill with sentinel x100 inhibitor.

Thankfully I have a towel rad in the bathroom which has a bung i can simply pour the above treatment into and my drain point is outside in the back garden which is handy.

The procedure is well documented on the internet and there is also several vids on youtube which i have watched and want to proceed with doing this tomorrow.

As a final precaution before I started draining the system I thought id check the Vaillant maintenance manual which again describes the process as i expected from previous guides but i do however have the following questions.

1. Directly below the "filling the heating" instructions there is "Purging the heating system" which instructs you to run a "Purging test program". What is this and will i need to do it after reflling and bleeding the rads?

2. The manual does not say to switch off the power to the boiler which is something i thought was required when filling. it instead asks you to keep an eye on the LCD display till you reach 1-1.5 bar. There is also an analogue pressure gauge inside at the bottom right. Should I switch off the boiler and use this gauge before powering it on or can i have the power on when filling back up?

3. In this section it states the "automatic air vent" which is used to purge the air in the system independently during operation. Mine is open half a turn at the moment, how should it be and do i need to do anything with it when draining/filling the system?

Would gratefully appreciate any advice and answers to the above so that i can proceed.

Thanks,

Mark

If I were you, I would not attemp this work, you obviously havnt got a clue as to what you are doing and it will all end in tears.
Save yourself alot of grief and get a competent engineer to do it for you.

It's easy enough to refill providing you have the auto air vent open and use the filling and bleeding programs. P6 and P0, they're in your book with instructions how to get them up.
It is important that you do them when refilling or you risk damaging your main heat exchanger, expensive.

Also, X400 needs to be in the system for around 4 weeks for best effect, if you're doing it in a day, I would use X800. This is what I done a few years ago and it worked quite well. I used the filling and bleeding programs too.

Read more: //www.diynot.com/forums/viewtopic.php?t=186348&start=0

Thanks guys. I will indeed run these programs as per the manufactures instructions P.06 (moved diverter valve to mid position) when draining.

Before filling run the P.06 test again then fill to 1-1.2 BAR. bleed rads from bottom up. then run P.00 test program.

confusion i have is that it does not state anywhere in the manual to switch off the boiler while draining or filling the system.

I assume that the P.06 puts the boiler into the state where it can safely be drained and filled as it disables the pump and burner while active.

Sorry for replying to an old thread, markyjones, but just wondered if you were successful in your efforts to drain your CH system. Any problems at all?

Thanks,

Mark

marktabs29 said:

Sorry for replying to an old thread, markyjones, but just wondered if you were successful in your efforts to drain your CH system. Any problems at all?

Thanks,

Mark

Click to expand...

He's not logged in since his last post on this thread 6 years ago so I'd be very surprised if you get a response

Hi Andrew,

Many thanks for the reply.

Cheers,

Mark