my Vaillant ecotec keeps coming up with f75?

Had the F.75 problem on the Vaillant after the key meter ran out.
Slightly different resolution, but just a variant on Zuby's theme, and its how I've solved the same problem on other boilers over 20 years.
Firstly, this is not a technical problem, its effectively routine maintenance. Its the 'Boiler Pressure is too low' cut out coming into play, which all modern boilers do if- the water pressure is too low. This happens for various reasons, a change in outside temperature/pressure in Winter often triggers it by ejecting water and thus lowering the system pressure. Its normal. (What isn't normal is the sub moronic way Boilers are designed without making this standard re-pressurising procedure bleeding obvious).
On the boiler we have, there are no white buttons, just a single screw valve on the steel flexi-pipe section in the copper pipes below the boiler- about 30cm below in this case. (This is how most of the boilers water pressure valves I've seen over the years are, some might have a small red screw tap instead).

So the solution to F.75 here: turn the valve 180 degrees anti clockwise, and watch the water pressure dial go up to about half way on the dial. Turn the valve 180 degrees anti clockwise to close it. [Practice turning it on/off like this quickly, because you need to close it BEFORE it goes into over pressurised]. Then switch the boiler off for a minute, then switch it on. It should now work- if the problem is purely water pressure. In my experience this is the problem/solution by about a factor of 20:1.

Rhoops
July 2016

ZUBY YOU ARE A GENIUS.

I had F75 water shortage. turned the knobs at the bottom of the boiler like you said. Now job done. Many thanks.

taz
March 2016

Switching it off and on worked for me. Then i test the water after I heared the boiler make a noise

craig
December 2015

i followed the instructions here and it solved my problem. Many thanks

sam
November 2014

Thank you so much! This simple solution worked for me and only took a few minutes to perform. =)

Nick
October 2014

I'll add my thanks to Zuby - you are a genius. Saved a lot of hassle and money on a cold Sat night with no heating or hot water! I followed Zuby's instructions after getting an F75 error on an Ecotec 831. Like others, I spent a lot of time looking at useless pages and videos until I thankfully found this page. I had bled the radiators earlier in the day, so presumably this caused the pressure sensor to get confused.

Here are Zuby's words of wisdom again
"Here's a summary: the problem is to do with low pressure in the system. I hadn't noticed that the pressure gauge was showing almost 0 bar.

Underneath the unit there are two white knobs with Closed on them. Open the left hand one, then the right hand one, watch as the pressure rises to about halfway up the dark grey area on the gauge. Then close the right then the left knobs.

Press the "-" button next the the radiator control will show the pressure in the system. This should be between 1.0 and 2.0 bar.

Then i switched off the boiler, waited for 1 minute and then switched it on. All worked well."

PS - make sure that the two white knobs both have 'closed' facing to the front after you have repressurised

Davie
April 2014

Bought in 2005 Echo tech plus showing f75 code .. Pressure gauge is fine... What could be the reason

Kumar
February 2014

I have an ecoTEC plus 937 (the boiler model with a hot water tank slung on the back). It was also suddenly showing an F.75 error message with insufficient pump pressure, meaning we had no hot water or heating. I followed the instructions on here (open left white knob under boiler, then right white knob, then close them in reverse order). Worked a treat, so many thanks to all of you who have posted. Only other issue I had was that my boiler has a complex digital display and I couldn't get pressure readings to show whilst I was using the two white knobs to top up the water. My solution was to top up gradually until the F.75 error didn't recur, then to add a bit more water. With everything working again, I'm able to check the pressure properly and have topped it up again to just below the maximum line on the pressure display. One other piece of useful info: the error showed approx one hour after I had bled all of our radiators, so (as others have posted) that was almost certainly the cause of the problem. Thanks again all.

Jon in Leeds
February 2014

Follow the simple instructions from Zuby, after searching the internet and watching some very poorly made instruction videos (that left me non the wiser), Ifortunately, discovered this forum. Zuby's instructions saved the day! Within 2 minutes the heating was back on. Thank you so much! Why they don't have this in the instruction booklet is anyone's guess. Can only imagine how many people have called out an engineer to fix this simple problem...

Miss J G
January 2014

Thanks so much. This helped get mine working again so I could have a shower on Christmas Eve before I go to work.
Again a thousand thankyous.

Sean
December 2013

I can tell you how to fix the error f.75. It can be either of two things.

Trevor
June 2013

Thank you so much. I had error F75 and the advice here has helped me get my ecotech pro24 running again. I just opened the water valve underneath and refilled until the pressure gauge was back into the grey zone. Thank you

Alex
April 2013

thanks for this amazing site. My Vaillant ecoTec pro stopped working last night, showing f22 error code. I couldn't find the filling loop (boiler in work has a loop). Thanks to you I now know that my boiler has 2 plastic knobs. The manual doesn't mention these! Heating is now working again, all cosy & warm!

Pat, Bristol
February 2013

I have an ecotech pro 24 and first flashed a f75 then f22, I kept on reading solutions to the low pressure on boilers that have the 2 white plastic knobs to turn but I have none of those but 2 flat connections that can be turned by a screwdriver attached to hose loop.....then I came up to this forum and my problems were solved......it's the same technique of opening the left screw connection followed by the right and run the tap water and you will see the bar raising up to the grey level.....THANKS SO MUCH!!!! And by the way, I am a girl so proud of myself!

Riva73
December 2012

On mine its saying f75 but the pressure is fine. any ideas?

girl82
June 2012

We're a group of girls in a rented house and we did this and are so grateful. Our landlord was useless. However our pressure now says 2.2 which is obviously higher than stated after an F75 issue. It's not in the red zone but right at the top of the grey dial. Is it ok or do we need to change it, if so how?
thank you

girls at 44
February 2012

Panic!!..Thinking this is gonna be costly and couldnt find in the manual 'F 75'...2 mins on here and Hey Presto...were getting warmer and hot water!!! And im a girly!! Thank-you soo much for solution, who'da thort drop in water pressure+turn boiler off and on again...

Niki, Staffordshire
February 2012

worked for me at 6am this morning when it was -5 outside, many thanks

Mark Hebby ,YORK
January 2012

Had the same prob f.75. Read the manuel for ages and none the wiser, 2 minutes on here and hot water and heat. Thanks for the solution !!

Danny
December 2011

I got an F.75 error on my Vaillant 'eco TEC pro' on the screen; and the red light was on.

Thanks to the answer available in this forum, i was able to fix it and saved a lot on a call out charge.

Here's a summary: the problem is to do with low pressure in the system. I hadn't noticed that the pressure gauge was showing almost 0 bar.

Underneath the unit there are two white knobs with Closed on them. Open the left hand one, then the right hand one, watch as the pressure rises to about halfway up the dark grey area on the gauge. Then close the right then the left knobs.

Press the "-" button next the the radiator control will show the pressure in the system. This should be between 1.0 and 2.0 bar.

Then i switched off the boiler, waited for 1 minute and then switched it on. All worked well.

Zuby
April 2011

Thank guys! my f75 problem solved in 2 min with your advises!and i'm just a weak woman ;)

Gos
January 2011

Is closed when the White knob on the right is horizontal to the front? Or sideways? How do I know how its open or closed?

Lumazzcc
January 2011

I got f22 error too after mains shut down. A little stressed until I found this. Pressure bar low until I turned right knob under boiler written closed. Pressure rose to grey! Yipee problem solved! Thank you!!!!

Pamela
January 2011

Thanks guys for the info! great stuff, anyone reading this today make sure that you have a tap running or the pressure knobs will not allow you to increase the pressure, be sure to reset the system with tap running, then increase pressure up to 1-2.

Merry Xmas all! :)

Phil
December 2010

My ecoTec was constantly giving me an F75 error. Usually a switch off/on fixed it but after reading the instructions here I have fixed it.

Here's a summary: the problem is to do with low pressure in the system. I hadn't noticed that the pressure gauge was showing almost 0 bar.

Underneath the unit there are two white knobs with Closed on them. Open the left hand one, then the right hand one, watch as the pressure rises to about halfway up the dark grey area on the gauge. Then close the right then the left knobs.

Press the "-" button next the the radiator control will show the pressure in the system. This should be between 1.0 and 2.0 bar.

This probably saved me a fortune in a callout charge.

Peter H.
December 2010

Mine is an ecotec pro... kept coming up with F22 after bleeding radiators. now mine doesnt have the grey valves in the boiler but external to the unit between the copper pipes. thankfully the plumber left the mesh hose on... pity my landlord decided to box it all in... under a shelf... then decided to put a toilet infront of it and then box it in again... with another shelf. Didnt make it easy!!! but once topped up... and rebled the system... sorted! thanks for the help guys

Glyn Whibley
December 2010

did what it says on here and now works perfectly. Freezing cold morning with 2 little ones, saved me a load of grief from the mrs! Thank you Thank you

colddaddy
November 2010

The refill technique worked a treat for us too. Woke up to an f27 fault and having read a few forums tried restoring the airgap by draining down the megaflo tank but no joy. So checked on here having noticed low pressure reading on the ecotec. I tried opening the two taps on the braided hose one at a time and bingo I could hear the water filling inside the ecotec and saw the pressure go up into the grey zone. Waited a minute then switched on the timer for the hotwater and heating and hey presto - it stayed on and no fault code. Thanks guys!

Liam
September 2010

A big thank you to everyone here who shared their knowledge and experience. Mine played up with F22 error this morning and within minutes it was running again. Many thanks

dumbo
April 2010

Morning.. To my horror I woke up to cold water and saw on my ecoTEC the F22 error.. I called up for someone to come out and they cant do anything tomorow! So this has really helped me out.. I went to the taps under the boiler with 'CLOSED' and followed the instructions and voila it works!! Saved me sitting in the cold today and boiling kettles up!

Nina
April 2010

Thanks Scope - you took the pain out of that for me.

I love this site.

Lizzy
March 2010

ah f75 poss pressure sensor fault caused by magnatite in system or could be pump also caused by magnatite also, no problem with boiler get system flushed and fit magnaclean to system ,f75 =dry fire protection pressure sensor not sensing pump

super vaillant man
March 2010

Thanks for advice on error F 75 was cautios but found taps and two tics later red hot water again thanks for great advice saved me bill at xmas much appreciated

MALC. L
November 2009

Mine was coming up with F22 this morning (Vaillant EcoTec). After reading this I looked and there's no braided pipe on this model, BUT there are two plastic taps on the underside of the boiler body, both with "CLOSED" embossed into them. I opened the one to my left then the one to my right, heard the boiler fill, turned off the right hand tap once the grey area had filled by about four mm, and hey presto 0.6 bar reached, and the wife could merrily shower away our water bill. Thanks for the advice and guidance, couldn't have worked it out without you guys!!!

Scopes
June 2009

Simona, thank you so much for the solution to F22, were on the brink of desperacy, with a guy asking £80 to come out and take a look at it. We decline his service and followed your instruction and it's as good as new. Many thanks

HappyDG
May 2009

The boiler ECOTECHPLUS is 3 years old and 2 days ago on the screen came up the error F75.What is about?How much costs to repair it?Thanks

Simona
March 2009

Guys

Thanks so much for the advice! I had the dreaded F22 and was panicking until a few minutes ago when my boiler sprang back into life! I think I might have a newer model because all the pipe connections are clearly labeled...I just opened the 'CH flow in' pipe then turned on the taps in the kitchen and the lost pressure came back. The boiler's now working fine - fingers crossed!

Mike
March 2009

I gave my sister these instructions long distance over the phone when she went home after a vacation and she managed to fix the F 22 problem. Thanks Beatrice!

N
January 2009

I had the exact same problem when our boiler displayed the F22 error. Following these instructions got the boiler back on, and the house warm! Thanks for saving me calling out the plumbers again! ^_^

Shorty-Boy11
January 2009

Mine had the dreaded F22, but, thnks to your instructions, we're back in business! Just as a matter of interest, the guy that installed my boiler cunningly hid the filling loop at the other side of the loft, so I had a bit of pipe-tracking to do!

Jimbob
September 2008

We've just had the f22 error and these answers helped us (two very incompetent fools) to fix it! Thank you all very very much!!

us
March 2008

This advice worked for me, 24hrs on and no apparent problems so far. My boiler, fitted in summer 2006, only had the tap on the braided flexible pipe but the pressure soon became high enough to kick start the heating. Thanks

Mo
January 2008

Often the sensor on these models. Sensor is the pinky orange coloured one at the bottom left of the boiler. Needs to be taken out and blown through or replaced. Careful to drain down the boiler first or you will get wet!

Steve
October 2007

Beatrice you are such a star. We had the F22 error and were completely out of options bar calling a plumber. Thanks so much for that tip - how simple and I can't believe the phone muppet at Vaillant couldn't tell us that?

David and Hannah
August 2007

I had similar trouble with error code f.22 on my Vaillant eco-pro. After reading the solution to this question i gave it ago myself and it worked! Thank ou clf gas...

Use a screw driver to open the silver braided pipe (one one side) and then open the little tap(the other side of pipe) to let water into the system. The pressure bar should go back up to the grey area. Make sure that you let enough water get in until it reaches at least 0.6bar.

Should be happy days!!

Beatrice
March 2007

F75 on the ecotec range mean's....... no pressure when pump turns on...... either faulty senser or pump, or low pressure in the system .............. is the pressure guage above 1bar when cold (within the green) if not top up via filling loop underneath...(silver braided pipe with little taps).. if yes, one of the first two faults.......

clfgas
February 2007