DaveAndAnnaUK Posted January 24, 2022 Share Posted January 24, 2022 The system was finished and commissioned in January 2021 by professionals who commented on our excellent pipe fittings and general first fit of the whole house ventilation. In August to unit set itself in summer override and was continuously working on boost. When the weather cooled down, it didn't stop the boosting but the summer override light has switched itself off. We tried the 'turn it off and back on' trick but it didn't work. As the weather was fine we left the unit turned off for a few weeks but it would not turn back on after that. We contacted the makers and they said it could be the PCB or even the fan motors could have ceased. Long lead time on parts meant that it was left turned off again. Two weeks ago we were woken up by dripping inside the vertical ducts and we discovered that all the pipes were full of condensation, water and black mould and that the unit is full of fluffy white mould. Many ducts junctions were leaking and we had to disconnect the ducts and block the vents to try and dry it all out. Is it all completely ruined? what can we do next? how do we get rid of all that mould? What do you think? Link to comment Share on other sites More sharing options...
Surfdude Posted January 24, 2022 Share Posted January 24, 2022 Blimey, that's looks a mess. Who was the manufacturer? And was it installed by them? Link to comment Share on other sites More sharing options...
jack Posted January 24, 2022 Share Posted January 24, 2022 Welcome to the forum. That's very unhappy-looking MVHR system you have there! How long did you leave the MVHR system turned off, and how have you been ventilating the house during this period? How was it left with the supplier? Did they advise what you should be doing while waiting for parts? It also seems odd that no effort was made by them to identify exactly what had gone wrong. I genuinely have no idea whether the unit is salvageable. It's possible that you can clean it out and disinfect it sufficiently that it can be used again, but getting at the insides of the distribution pipework in the rest of the house may be an issue. Do you have a semi-rigid system? If so, is it circular in cross section? It's possible that with a lot of time and energy you could clean and disinfect the insides of such ductwork (I vaguely recall someone once talking about duct cleaning a few years ago), but it may not be a job you can do yourself. Link to comment Share on other sites More sharing options...
thefoxesmaltings Posted January 24, 2022 Share Posted January 24, 2022 31 minutes ago, DaveAndAnnaUK said: The system was finished and commissioned in January 2021 by professionals who commented on our excellent pipe fittings and general first fit of the whole house ventilation. In August to unit set itself in summer override and was continuously working on boost. When the weather cooled down, it didn't stop the boosting but the summer override light has switched itself off. We tried the 'turn it off and back on' trick but it didn't work. As the weather was fine we left the unit turned off for a few weeks but it would not turn back on after that. We contacted the makers and they said it could be the PCB or even the fan motors could have ceased. Long lead time on parts meant that it was left turned off again. Two weeks ago we were woken up by dripping inside the vertical ducts and we discovered that all the pipes were full of condensation, water and black mould and that the unit is full of fluffy white mould. Many ducts junctions were leaking and we had to disconnect the ducts and block the vents to try and dry it all out. Is it all completely ruined? what can we do next? how do we get rid of all that mould? What do you think? Wow. Not the image of what you'd call a "healthy ventilation system"! Did you use flexible ducting or the fixed metal ducts? This is my concern with all of the newer technology...it's just one more mechanical thing to go wrong in a house, and MVHR is absolutely critical to an airtight build....In fairness this is the first time I've read and seen an MVHR system going mouldy. Apologies, not much advice to give I'm afraid, but will follow the thread for learnings if you don't mind. Also would be interested to know the manufacturer and installer. Link to comment Share on other sites More sharing options...
Declan52 Posted January 24, 2022 Share Posted January 24, 2022 Are all the ducts fully insulated if they go via any cold areas of the house like the loft. I had a similar issue with a build up of water, no where near as bad as you have, and this was due to not having enough insulation over a section of duct that was in my eaves. Once fully wrapped it's had no further issues. Link to comment Share on other sites More sharing options...
Mr Punter Posted January 24, 2022 Share Posted January 24, 2022 I think you need the manufacturer out to look at this. Was it a DIY install? Which ducts are an issue (extract to unit, exhaust to outside, intake from outside, supply from unit)? Is the unit located in a heated space? Link to comment Share on other sites More sharing options...
Iceverge Posted January 24, 2022 Share Posted January 24, 2022 It might sound like a silly question but were the filters OK? I know our first set only lasted a month or so after we moved in. A blocked set might have confused the MVHR unit. In the meantime maybe get 2 inline fans and extract from all the house ( supply and extract) and leave windows on the latch for trickle ventilation. It should suck all the moisture our of the ducts and kill the mould as well as giving you some needed ventilation. My suggestion for cleaning the ducting use a vacuum to draw a string through the ducting to/from the manifold. Then tie a rag firmly on one side and pull it back to clean the ducting. Start with a smaller rag and work up until you have something that cleans well but does not get stuck. Link to comment Share on other sites More sharing options...
Temp Posted January 25, 2022 Share Posted January 25, 2022 Our stopped working after about 6 months. Turns out filter was blocked and it had blown a fuse in the speed control unit. Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 26, 2022 Author Share Posted January 26, 2022 Hi all, Dave here(The blind one), Sorry for not replying sooner. We have a video of the installation, but it is too big to post here. Please could someone recommend the best way to give you all access to the video. Cheers Dave Link to comment Share on other sites More sharing options...
jack Posted January 26, 2022 Share Posted January 26, 2022 1 hour ago, DaveAndAnnaUK said: We have a video of the installation, but it is too big to post here. Please could someone recommend the best way to give you all access to the video. You can upload it to YouTube and post the link here. Use a throwaway account if you want to increase your privacy somewhat. Link to comment Share on other sites More sharing options...
joth Posted January 26, 2022 Share Posted January 26, 2022 1 hour ago, DaveAndAnnaUK said: Hi all, Dave here(The blind one), Sorry for not replying sooner. We have a video of the installation, but it is too big to post here. Please could someone recommend the best way to give you all access to the video. Cheers Dave Post it on YouTube and put the link here? Various file sharing sites could also work (Dropbox et al) but they're a bit more bother to use. you may be able to share it via photo sharing platform of choice (Google Photos, or whatever the Apple version of that is) Link to comment Share on other sites More sharing options...
epsilonGreedy Posted January 26, 2022 Share Posted January 26, 2022 Is this a warning that those of us planning to install an MVHR in a cold attic need to put more effort into duct insulation? I know that most BuildHubbers are happy with their MVHR installations but warm roofs are also the norm here. Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 26, 2022 Author Share Posted January 26, 2022 (edited) link to the video, more pics later Edited January 26, 2022 by DaveAndAnnaUK Link to comment Share on other sites More sharing options...
epsilonGreedy Posted January 26, 2022 Share Posted January 26, 2022 (edited) An excellent video tour Anna. Is the property a new build or was the MVHR installed in a much older property? Was there an existing damp problem somewhere in the house prior to the installation of the MVHR. Do you have a properly installed & vented tumble dryer in the house or do lots of cloths get dried in radiators? Oh one last thought, is the MVHR machine disconnected in the main fuse box? I ask because I was a bit worried watching you touch the machine with so much water inside. Edited January 26, 2022 by epsilonGreedy Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 26, 2022 Author Share Posted January 26, 2022 This is something I am wondering too! The thing is, it hasn't been very cold, so if the beast from the east arrived, what would it be like then? Something els is the humidity on Portland is usually around 80%. I read the preferred humidity level should be between 33-50%. Well if the air coming in is at 80% or worse still, it is foggy, which is also common on Portland, then what chance do we have! Back in August, warm weather, the unit basically ran on boost all the time. The summer override lights were initially showing, but when the weather cooled it continued boosting with the summer override lights not showing, which is when I decided something was wrong. I contacted the company, who said either the PCB or humidity sensor could be at fault. They said I could disconnect the humidity sensor, but being blind and my wife not wanting to play with it in case of cutting wrong wire, we left it alone. Then we turned it off for an hour and turned it back on. The unit again ran on boost and was left on to see if it was going to slow down. It didn't and then we turned it off. After a couple of weeks we tried turning it back on and then nothing! Called the company and they said again it could be the PCB or as the motors are supposed to be continuously running, they might have seized! I got them to quote for parts as the unit was out of warranty. We purchased it back in 2016, but weren't able to have final installation and commissioning done until January 2021. This was due to me breaking one ankle after the other. One of them now has three plates and fifteen screws in it! Plus lots of other rubbish getting in the way, resulting in us having to get the builders in to finish. So back in January 2021 the unit was as new and a commissioning certificate issued February 2021. Nothing was said about changing filters earlier than at normal service intervals and so we let it do its thing and here we are! Not happy! 1 Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 26, 2022 Author Share Posted January 26, 2022 22 minutes ago, epsilonGreedy said: An excellent video tour Anna. Is the property a new build or was the MVHR installed in a much older property? Was there an existing damp problem somewhere in the house prior to the installation of the MVHR. Do you have a properly installed & vented tumble dryer in the house or do lots of cloths get dried in radiators? Oh one last thought, is the MVHR machine disconnected in the main fuse box? I ask because I was a bit worried watching you touch the machine with so much water inside. Hi The house is a 1940s ex council house and has been totally stripped and refurbed. All walls over insulated and made as air tight as possible. All walls and ceilings are fermacell and windows triple glazed. Dishwasher and washerDryer are both condensing and only hang washing over bath if unable to hang outside. Due to insulation, only heating downstairs is a small oil radiator and a real flame electric stove. Upstairs has boiler fed radiators , which rarely need using. In summer we normally have all the doors and windows open as the weather is so nice. The biggest difference I noticed was the front bedroom which is south facing, didn't get as hot with the window closed. It was like an oven with the window and bedroom door closed when the sun was shining before. The unit is connected to a switched, fused spur in the loft. I'm waiting for Anna to upload photos showing the ducting installation in the wall and kitchen, living room ceiling. All the ducts are solid apart from those connected to the unit itself. Cheers Dave Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 26, 2022 Author Share Posted January 26, 2022 Hi Jack Sorry for not replying sooner, I have been sorting out all my emails into one folder, so I can easily check dates. I believe it was the last weekend in October that we tried turning it back on. So I would say it was sometime in early October we turned it off. The company gave no advice as to what to do with the machine when not working! I have had Anna look through the paperwork and she hasn't found anything other than it says the machine must be in continuous operation. Well if it stops, what action should be taken? Seal up all the vents? Disconnect all pipes from the machine?There should be a notice on the machine what to do and I did inform the company and nothing was said about what to do with a machine that wasn't working. While the machine hasn't been working we have had the windows open whenever possible, basically, back to life without MHRV. In the past we have been on holiday for four weeks at a time and if, in that time the unit was to fail, who would know? Until turning on the bathroom light and not noticing there is no boost, there would be no indication something was wrong. How long does it take for mould to form? As for the ducting, below the loft, everything is rectanglar and there isn't a cat in hells chance of cleaning it by hand. Are there any mice that like eating mould? LOL Well see if I can get Anna to upload more photos and then send a message to Mr Glover, the managing director! See if I can get his opinion since his employees weren't keen to provide his contact details! I'm sure they could do better than send an email to enquiries@.... FAO ! Cheers Dave Link to comment Share on other sites More sharing options...
Iceverge Posted January 26, 2022 Share Posted January 26, 2022 I wager that if you were to connect something like this to both the extract and supply sides and leave it run on extract like MEV for a month the mould and damp would all disappear. Link to comment Share on other sites More sharing options...
MJNewton Posted January 26, 2022 Share Posted January 26, 2022 (edited) It does sound like it's just lack of use that's led to condensation forming in the ducting, particularly given it is inside a cold loft (insulation only slows the rate of heat transfer and so given long enough even the thickest of insulated ductwork will cool down). I think the installation looks fine on the face of it too. Sure, perhaps joints could be taped/sealed and maybe more insulation applied (e.g. rockwool wrapped around everything you can) but it looks like someone has put some effort into installing it. It certainly is nothing like the shockers we see from time to time and that are easy to find fault with. If the unit isn't working then, yeah, maybe you could go down the route that Iceverge suggests to get some air moving inside the ducts. But I think I'd focus on fixing the MVHR as it's a most worthwhile system to have, particularly in winter. Have you braved opening the front panel of the unit? I'd be particularly keen on seeing how well the condensate drain is working - or not. Just brace yourself for more mould which might require the heat exchanger removing to allow a thorough clean. I'm sure you can save this. Edited January 26, 2022 by MJNewton Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 26, 2022 Author Share Posted January 26, 2022 MJNewton, I tried opening the front of the units, removed all the screws but it won't budge at all, I suspect is it somewhat corroded to the main box due to the amount of water inside it. Anna Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 28, 2022 Author Share Posted January 28, 2022 Hi Dave writing, on the evening we discovered dripping, well I'm blind and so tend to hear things more than others! I went into the loft with Anna and felt the pipes. They felt warm to the touch which I thought was wrong as it was only around five degrees in the loft and immediately thought the insulation wasn't up to the job. All the flexible pipes that connect to the unit have what I call thin insulation which isn't sealed either end. I wonder what they use in Canada, where temperatures are far lower, minus twenty as it is now in places. Have you seen the truckers convoy? As for getting in the unit, Anna has tried and God knows what it might be like in there! I'd rather not know as I'm already annoyed enough as it is. Wonder how many have had a look at their units, to see if they too have any mould growth. I would like to hear from them if they have. The pipes clearly aren't insulated enough and I'm betting the unit itself isn't insulated enough to stop condensation on the inside. I wonder how much research went into the design of these systems. Non one turns a fridge off without leaving the door open or it gets horrible, pretty quickly. Well what are you to do with the MHRV if it fails? Its not sealed like a fridge! This is another point I am taking up with the company, there are no instructions on what to do when the unit fails and when I informed them the unit wouldn't start, no advice was given on what to do with it. For anyone who hasn't already had experience with MHRV installation and service, expect long lead times! Expect it to take months to have anything done! If I were to order a new unit now, it would be the end of April before it could be fitted. The installation company is three and a half hours away and so some of the cost is for seven hours travel time. This is something else, the company selling the MHRV system doesn't install it Plus the installation company won't connect the condensate drain! Have to have a plumber connect it and send them a photo for them to send the commissioning certificate! Ridiculous ! By trade I have been a mechanical maintenance engineer and then an aerospace engineer, so before losing my eyesight I used to do everything both car and house. I hate garages and I hate dishonest tradesmen! Whenever I took a car to a garage I ended up fixing it myself. I did most of the work on the house having friends and neighbours helping with what I couldn't see. Again when builders had to do jobs for me, I would find the problem! Builders don't seem to know how to use spirit levels! Have you noticed this? I'm forever being told it doesn't need to fly! well my friend and his son fitted a new shed roof and it flew off in a storm, so of course I told them it wasn't supposed to fly. Why am I telling you this? So you will realise how annoying all this is when you trust a company to design a system and then another to install and commission, then discover it clearly isn't up to the job. I used to make planes and you know what happens if they fail! What was the purpose of installing MHRV? To avoid installing trickle vents! What's the point of triple glazing and then putting holes through the frame that also allows noise through. Second to constantly have clean fresh air. Well, now I know the ducting contains mould, so now the system itself is a health risk! Which neither I nor anyone else could see. I have sent an email to the managing director and have been contacted by the person assigned to deal with my complaint, so we will see what happens. Hopefully lessons will be learnt and designs improved so others don't suffer the same fate. Thankyou for listening. Ok nurse Anna, what's for supper? Cheers Dave 1 Link to comment Share on other sites More sharing options...
epsilonGreedy Posted January 28, 2022 Share Posted January 28, 2022 On 26/01/2022 at 13:51, DaveAndAnnaUK said: Well if the air coming in is at 80% or worse still, it is foggy, which is also common on Portland, then what chance do we have! The warming of the supply air will reduce the humidity level, some MVHR owners find the resulting lowering of internal humidity to be a problem. While waiting for experts to visit could you acquire the gadgets to accurately measure the current humidity levels in your house? Link to comment Share on other sites More sharing options...
Radian Posted January 28, 2022 Share Posted January 28, 2022 2 hours ago, DaveAndAnnaUK said: By trade I have been a mechanical maintenance engineer and then an aerospace engineer, so before losing my eyesight I used to do everything both car and house. I hate garages and I hate dishonest tradesmen! Whenever I took a car to a garage I ended up fixing it myself. I did most of the work on the house having friends and neighbours helping with what I couldn't see. Again when builders had to do jobs for me, I would find the problem! Builders don't seem to know how to use spirit levels! Have you noticed this? Yes I have noticed this. They are particularly bad at understanding the limitations of using bubbles to get things plumb. I regret having nothing practical to say to help you but I sincerely hope you get the resolution you deserve. Link to comment Share on other sites More sharing options...
DaveAndAnnaUK Posted January 29, 2022 Author Share Posted January 29, 2022 Anna has some humidity sensors that need new batteries, so I'll have her sort them out. Please could everyone reading this who has a MHRV, please read their instructions and see if they say anything about what to do if the unit fails. Considering my experience of lead times between two to three months, there is easily enough time for mould to grow, as we have found. Have the manufacturers bothered to consider this when designing the system? Anyone done a quick check on their system (Working!) to see if there is any mould? Not got much to do this weekend, so might as well do some research. Anyone got links to building research studies? Found some the other day, but they were to coffee morning chats on Zoom. Do you have loads of website bookmarks? Try out LIRE, it makes life so much easier keeping up to date with the latest articles from your favourite websites, unfortunately this one doesn't work with it for some reason. Well Portland was 10 degrees and 91% humidity this morning at 08:30. Will get the sensors sorted and see what the difference is inside. Cheers Dave Link to comment Share on other sites More sharing options...
MJNewton Posted January 29, 2022 Share Posted January 29, 2022 I see inside my unit every six months when I change the filters and it's always fine (but always working so to be expected). Link to comment Share on other sites More sharing options...
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