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Discuss Boiler Heating too quickly (MAIN combi 30 eco) in the Central Heating Forum area at

  1. junxs

    junxs New Member

    Hello Everyone,

    I'm just looking to get some advice please.
    I've had my boiler installed about 4 years ago (MAIN Combi eco 30 - MAIN being a subdivision of Baxi), and it has just started giving me some problems in the last couple of years.

    Recently the pressure was constantly dropping as the overflow pipe was dripping non stop. I had SSE come out to fix the problem for a one off £150 charge (which was advertised as parts and labour). However when the chap came out all he did was drain the system, take off the Pressure Release Valve, gave it a good clean and put it back in. Just over a year later the same thing started happening again so I thought I would save myself a bit of money by just doing the exact same thing myself.

    Now I did this quite easily, but after putting the water back in the system - I have found that yes I have fixed the pressure dropping issue, but now the boiler jumps to 72 degrees (my set temperature) in no time at all, I'm talking like 2 minutes.. this used to take like 25 minutes before.

    Its leaving all the downstairs radiators cold, but the ones upstairs are getting nice and hot (there is no zonal system).

    I know you are all thinking I should have left this to the pros, but to be honest I felt a little ripped off last time for what was half hours work so thought theres no harm in trying it fix this myself. In the past I have fixed my oven by replacing the heating element in it, fitted a new shower myself, fixed my washing machine, and lots of odd jobs around the house, so I'm quite capable - and I thought it was worth giving it a go.

    So my question now is, is this a simple fix? - I'm thinking I may have caused an airlock when refilling or something, or is it something more than that? Bearing in mind there were no other issues before cleaning out the PRV (which was full of gunge by the way and is now not leaking).

    Any advice will be much appreciated.
  2. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    The £150 price was a fixed price repair , you wouldn’t be complaining if the engineer put £300 of parts and labour in for £150.
    • Like Like x 2
    • Agree Agree x 1
  3. junxs

    junxs New Member

    Well thats not really the point I'm making.. but if thats the only thing you want to discuss from all that I wrote then I have to say it wasnt a proper fix as it started leaking again a few months after he "fixed" it but then it just stopped a few weeks later, then came back and stopped. The leaking stayed away during the summer, but became constant the very next winter after he had "fixed" it, perhaps he could have replaced it or theres a bigger issue causing the build up of yellowish gunge, maybe if he spent more than half an hour in the house he could have identified the bigger problem.
    I did call SSE again to ask them to come and have a look again but they wanted me to pay again despite it being the exact same fault that they "fixed" just a few months earlier. But I didnt really want to go into all of this. I'm just interested in advice on how to fix the new issue.
  4. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    I know that wasnt the point you were making but sorry you asked for the fixed price repair , and he repaired it .
    Most of not all manufacturers give a one year guarantee on parts and labour , you said it went after a year , not a few months .
    The reason he didnt change it was probably because he didnt have the valve on his van , theres loads of them , we would have to drive around with vans the size of furniture vans stocked with thousands of pounds worth of stock to keep parts for every boiler.

    As for the problem , there is something else what needs looking at in the boiler , if this is checked and is ok then I would put a new prv in , however because of the law and forum rules we will not and can not give any advice and encourage you to fix your own boiler .
    Rather than go with of the “big “ firms ask you friends, neighbours, work colleagues etc if they could recommend a local guy.
    • Like Like x 2
  5. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    It's clear you have poor circulation. As to why is anyone's guess, and without physically checking the system over all we can do is guess. Yes it could be an airlock, quickest way to sort this is run your system and turn off all the radiators that work, if there is any air in the system stopping the other radiators then that should sort it. You also mention your prv was gunked up, did the installer fit a magna clean or any other filter? Was the system flushed before install? If not the pump could be gunked up itself, or weakened by a couple years of trying to force crappy water round a system.
  6. junxs

    junxs New Member

    Thanks Townfanjon

    I appreciate you cant give exact advice otherwise people would go out of business, but im certain no other parts need replacing. Was looking to see if there was something more simple causing the issue as apart from the leak everything else was working fine before, i just had to keep feeding more water every 3 hours or so to keep the E119 low pressure error away. Some videos on YouTube suggest a balancing of the radiators if the upstairs ones are hot and downstairs ones arent, though thats partly my problem theres nothing I can find on why the temperature display shoots up on the boiler within 2 minutes - cant understand why cleaning of the PRV has caused this. Thought there might be a very easy fix like releasing air out of the boiler by turning a screw on a valve or something.

    I did initially write my vent about SSE and went into full details, but before posting my opening post I decided to take it all out as I realised the opening post was too long after reading it back. Well the exact thing they said to me was you have to pay again and if we find that its the exact same fault we will refund you, but I felt they would twist their way out of refunding me by claiming there was something else and not admitting to it being the same fault.
  7. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    No no no its not people going out of business , it is safety , the people coming on here wanting advice on boilers when they have no idea what they are doing is frightening.
    • Like Like x 1
    • Winner Winner x 1
  8. junxs

    junxs New Member

    Thanks Craig, yeah what you suggest is similar to what I've watched in video just now and is something i'm going to do when I get home this evening.
    I do have a device under my boiler that collects gunk, I actually cleaned this out at the same time as I cleaned the PRV. It did have gunk but not a ridiculous amount. Its a red cylinder that a heavy magnet sits inside, I cant remember its exact name but it was awkward cleaning it as the rubbish just didnt want to come off so took a while but I cleaned that with luke warm water like the installer advised me to.

    I'm not sure exactly what a flush is, but they connected a pipe to my hallway rad and ran it outside and emptied the system? I've actually had 4 new radiators put in since then though, well 3 of them were replacements in the same location and 1 fresh one in a new room I had built. But the leaking didnt start until well after all this work was done.
  9. junxs

    junxs New Member

    Ok so I've just come home, no one else has been home. The heating has been off yet my boiler temperature is showing 74 as it's resting temp. This is obviously incorrect as the rads are cold and I had the heating off using my app from work. Just ran the hot water tap (after taking the photo) and it took a while to get warm but the temp and display dropped to 66 then came up into the 70s again.

  10. shyguy2005

    shyguy2005 GSR

    Get a gas engineer in.
    • Like Like x 1
  11. DGT plumbing

    DGT plumbing GSR

    Are you Gas Safe?
    • Agree Agree x 1
  12. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    How are you certain no other parts need replacing??
    • Like Like x 2
    • Optimistic Optimistic x 1
  13. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    Lost me pal lol
    • Like Like x 1
  14. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Sorry quoted the wrong post mate. Meant to quote OP as they said they were certain no other part was required.
    • Funny Funny x 1
  15. Matchless.plumb

    Matchless.plumb Trusted Plumber GSR

    How c9mes you start fiddling with a boiler without being registered? Did I miss a thing here or are you going g to ask professional people on here who have paid fortunes for their education and much more important the sweat and pain to gain the most valuable which is the experience just to fix your own boiler? If you do not hold a gas safe registered license you aren’t allowed to open up the the boiler cover. And yes if somebody comes on here to ask experienced engineers about boiler faults etc you need to be aware you’ll get snappy answers like mine without going into your long thread. You should be seeking a professional like the guy who has given you a fixed price which lasted a while.
    • Like Like x 1
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