Monday 17 January 2011

Baxi Duo-tec Combi Boiler E119 Low Pressure Fault

Although I’m going to talk about a low-pressure problem if you have the Baxi Duo-tec Combi Boiler then well done as it was voted Boiler of the Year (gotta love that title) 2008 at the CORGI Awards.  The award is voted for by the people who work with it on a daily basis.  The boiler was also awarded a 'Best Buy' by Which? in 2007 achieving the top score.

E119 low pressure fault
Let’s get to the recent fault and I hope this helps someone.  We have had this boiler for 3 years and very occasionally in the past it has lost pressure and switches itself off displaying an E119 fault on the display.  Reading the user instructions this was easily solved by re-pressurising the system and something you can do yourself.

This picture shows the display and pressure dial on the boiler.  (Cam: C902)

Recently though the E119 fault is occurring with more frequency.  The constant loss of pressure would indicate a leak somewhere in the system. The leak is either going to originate in the boiler or in the pipework and radiators.

First job then is to switch the thermostat down low so it will not call for heating.  Re-pressurise the boiler to 1.5 bar and then turn off the flow and return valves under boiler. This then creates a break between the boiler and the rest of the system and allows you to problem solve.  Leave it an hour or two…… A pressure drop on the dial indicates a leak in boiler.  No pressure drop indicates a leak from somewhere else, ie the pipework or radiators. 

Where is the flow and return valves?
Look under the boiler front at the pipes from the boiler, the 2 large ones 22mm will be flow and return to your CH system. The 3rd large one in the middlish is the gas pipe. Looking at my picture below you can see the valve on each pipe, turn these to a horizontal position to isolate the boiler.

The flow and return valves under my boiler.  (Cam C902)

In my case the pressure continued to drop indicating the leak was on the side of the boiler. I had laid some kitchen roll under the boiler to identify any drips.  From this I could the see the connector that was leaking and which required a quick tighten. Once I was happy that the leak was fixed the flow and return valves could be turned back on and the thermostat raised so the heating kicks in. I was lucky this was an easy fix.

If there is no pressure drop on the boiler dial then it’s time to check pipe joins, the radiator taps, bleed screws and any other joins where there could be a leak.  The signs of water seepage should be easy to detect with a finger or piece of kitchen roll.  Once the leak is detected you can take whatever remedial action is required.

Here is a bit of info from the manual.
E119 is displayed when the primary water pressure is less than 0.5 bar. After re-pressurising the system the boiler should operate.  The normal operating water pressure is between 1 and 2.0 bar. If the pressure exceeds 3 bar the safety pressure valve will operate and a fault is indicated.

Re-pressurising the system
It may be necessary to re-pressurise the system occasionally. A filling device (the filling loop) will be fitted on the system. This will be on the boiler itself, or on pipe work near to the boiler.  If you are unsure of its position, or cannot identify it, consult the installer who fitted the boiler.
The filling loop consists of two taps and a separate copper pipe with connection fittings. Only when re-pressurising should the copper pipe be connected between the two taps. (Note – I keep mine attached all the time).
Here’s the filling loop in situ  (Cam: C902)

Fully open the tap while watching the pressure gauge, when the needle on the gauge is indicating 1 or more turn off the tap.  Disconnect the copper pipe from the taps (Note – as I say I keep mine attached) and remove it. Keep the pipe in a safe place for future use.

Good luck if your in the same situation.

A word about frequent depressurizing.  If you find no leaks anywhere  my guess would be that your expansion vessel has lost pressure. The expansion vessel, or expansion tank, is the small tank used in closed hot water heating systems that helps to absorb water pressure. If it's lost it's 'charge' then as your water heats up the pressure builds and because the expansion vessel isn't doing its job then the PRV kicks in to protect the system and this will give a E119 fault. Theoretically you can recharge the expansion vessel yourself , but this is a job best left for an engineer.

35 comments:

  1. This is great information! I got my boiler restarted in 5 minutes, you saved me a pile of trouble. Phillip

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  2. Hi Phillip, glad it helped you out and saved you some money too. Thanks for taking the time to comment. Cheers Sean.

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  3. I googled and clicked and thanks very much to you my heating's back on again!!!!!! So very grateful!!!

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    1. Hi, no problem, thanks for taking the time to comment.

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  4. Just wanted to say thanks been to workout how to do this since I moved in.

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  5. Hi Alan. Thanks, and glad the information helped.

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  6. Brilliant, really helpful... Thanks

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  7. Hi Jeni. Glad I could help. Thanks for the feedback. :-)

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  8. Brilliant.working fine by following you information.Thank you

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  9. We have the E119 problem and are repressurising every 30 mins! It appears to occur if the boiler cuts out due to the thermostat but can also occurr just on its own. Research (incl your VERY helpful one) shows water leak, possibly via the PRV. Our PRV appears to have been plumbed into a drain. Is this normal? What could be the cause of the constant outage? Its driving us crazy. Only good side is it maybe saving us some gas! Does the temperature / gas intake control make any difference? WE have it on around 40%. Guy & Nika

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    1. I did my reply below instead of pressing the reply button, Doh! See below for your answer. :-)

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  10. Hi Guy and Nika. It's awful when things don't behave themselves isn't it. Let me answer the easy ones first. The PRV in to a drain, ours just goes outside and the water would go onto the path so in to a drain sounds tidy. Would temp / gas intake make a difference, no not in my opinion.

    OK, depressurizing every 30mins. My guess would be that your expansion vessel has lost pressure. The expansion vessel, or expansion tank, is the small tank used in closed hot water heating systems that helps to absorb water pressure. If it's lost it's 'charge' then as your water heats up the pressure builds and because the expansion vessel isn't doing its job then the PRV kicks in to protect the system and this will give a E119 fault. This would fit with your problem.

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  11. Theoretically you can recharge the expansion vessel yourself (with a bicycle pump apparently !!) Never tried it so I wouldn't want to advise on that, sorry.

    Good luck though :-)

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  12. hi, I repressurize my boiler afterE119 fault but Im not sure how the taps on the filling loop should be facing when they are off?I dont want left them open all the time.(my fiilling loop is also attached all the time)

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  13. Hi everyone really need some help please! Have a baxi 28he a...Haverepressurrised loads before but everything is all scrambled...Thank the toddler. So I have 2 red taps on the wall both vertical, then under the boiler i have 3 black taps all facing the door these are nearest the wall. Nearest the door I have 2 black taps both pointing down, can someone tell me where they should all be please!! Can send pics of needed, thanks x

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  14. Do I have to switch off my boiler before the repressure procedure or it is not necessary? Do I have to reset my boiler after the repressure procedure?

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    1. Hi Arpad
      No, repressurising can be done with the boiler switched on but turn your room thermostat down so it doesn't call for heat. However, switching off will do no harm (as would resetting) if you feel better doing that. Hope that helps.

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  15. Hello, Your information helped me months ago and now I now how to do it. The problem I have now is that I opened the water valve to re-pressurized but the water is not flowing! What could happen. Can you help?

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    1. Hi. The filling loop is connected by two taps have you tried both?

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  16. Hi, We have a DUOTEC COMBI 40HE A. The problem is that when the boiler is up and running after a short while it starts "BOOMING". Pressure is up to standard. Partially solve problem by turning down the water temperature, but this sorts it out only for a short while

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  17. Hi, I have a Baxi 28, and last year there was a regular pressure drop over a day or two. The filling loop is fitted outside the boiler (to the top right) and is a flexible pipe connected to the mains by an isolation valve (which has a small tap) and connected to the boiler by a one-way valve. There was an increasing leak at the isolation valve on the loop so I bought a replacement loop (complete with both valves). After fitting this, the leak stopped and the pressure remained steady for months.

    Then a couple of weeks ago, the pressure started dropping, at first every few days, then every day and now several times a day. There does not seem to be any obvious leak, except for a few drops at the nut where the copper drain joins - this pipe goes through the wall and is open outside. I am puzzled whether the present pressure drop could be associated with the previous one last year. Could you advise me please?

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    1. Hi Hadwen. My only thought is that when your heating is on, the pressure is getting too high and therefore expelled the water and produces a low pressure fault. This sometimes indicates the expansion vessel has lost pressure. See my reply on the 15 Jan 2015 above.

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  18. Thanks, Sean. I really appreciate your help. I need to bring in a professional to service the boiler. I read somewhere that it is illegal for an unqualified person to remove the cover, so I won't risk that.

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    1. Hi Hadwen. Sometimes that is the wisest decision. Good luck šŸ‘ Sean.

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  19. Brilliant, clear, simple. Thank you so much for making something that seems so complicated an easy task.

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  21. Brilliant! Took us a while to find a picture that exactly matched our set-up, (yours), and seconds to re-pressurize. Many thanks for you post.

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  22. Hi Sean, here is hoping your still problem solving. So I have a Baxi Duo Tech Combi 33 HE A. Since yesterday i noticed my pressure dropping significantly and an error code showing as the pressure had dropped from 1.5 bar to the red zone. I refilled the pressure to 1.5bar again and withing hours it was showing an error code again. I have checked all radiators and there is no leak. The only two things that happened yesterday was the kitchen fitter tripped the electric and the boiler was off for a few minutes and he also fitted a shelf in the cupboard that the boiler is situated, close to the valves and possibly knocked one of the valves. I have since noticed the slightest of drips as the shelf he fitted was slightly wet (I am yet to determine where this is coming from as the drip is that slow). I have also checked outside and there is no water dripping from the overflow pipe. I have the heating switched off but the pressure still drops over a few hours. I bled the radiators, 2 or 3 of them spluttered some black stuff out before the water ran clear. Despite me bleeding all radiators, which now instantly flow with water, there still appears to be air in the rads as i can hear it spluttering, on one rad in particular. I took out 1.5ltrs of water from this rad but i can still hear some air in it. Any help would be greatly appreciated. Thank you, Wayne.

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    1. Hi Wayne. I'm no heating engineer but if the rads flow as soon as you bleed them then I doubt there's air in them. May be more investigation needed about the noise.
      As for the pressure and the dip / wet patch, well that's got all the signs of a leak causing a loss of pressure. Need to stop the leak or call the boiler repair man šŸ‘
      Good luck, Sean

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