Blocked Plate Heat Exchanger Magnetite Sludge - Viessmann Vitodens 100 

Very professional diagnosis and maintenance repair. Felt very good to watch your progress.

Brilliant service Allen, I should think the customer was well pleased 😀

Those kind of jobs are really satisfying bet the owner was chuffed and you will have a return customer for life, it's all good.

Very good work, Allen! I wish more and more engineers to do their job properly, as you do. A friend of mine had the same DHW problem. He called the company that installed the boiler and they send some chaps. They did a flush to the main heat exchanger and totally ignored the plate exchanger that was sludged-up. The problem was partially resolved. He then called another engineer and he did all that you showed on this video. 🤘 👍

Allen's knowledge, skill and work ethic sets the high standard to which all apprentices should aspire.

Excellent. Very informative. This is good knowledge to help guide me in agreeing the go ahead of boiler repairs. I find some gas engineers seem to just keep replacing parts till it's fixed, or we just give up and replace the boiler. Repairs are expensive

I am waiting on a Viessmann gas engineer to do the very same thing . I have the same problem in spite of the boiler being serviced ?? every year .A great video to see and less messy than I thought ,thank you .

Good to see you servicing Viessmann boiler. I have 2 of them in my property. Seeing you repair them shows how good they are. Good luck with the Chenal.

Great video! Very clear and matter of fact. It's given me the information/inspiration I need to attempt this job on my boiler (I am an engineer with extensive DIY skills).

A really good video to watch Alan I’ve done quite a few of these on other peoples viessmann installs the ones I’ve fitted onto clean systems Have not had a problem at all, I haven’t tried a chemical yet that will remove the black sludge magnetite the only way I found to clean it is to plate off and jet wash it properly reverse flushing as well and the same applies to the main heat exchanger. I’ve got a VAX Aqua Vac which are used to suck dry the heating system water which you attach to the heating or the flow hose,or even the kitchen sink tap , It works a treat every single time. Viessmann Boilers are brilliant but you never see many well maintained

great vidio Allen this should be shown to all customers that are tight wads and dont want to pay that bit more for a proper service.

Very informative video Allen many thanks ~ the customer must be delighted I’m sure 😃

Allen is the best plumber on youtube, got a wiesman 111-w and 2 services later, still got the seal.

This video saved me! I live in Canada and I have a Viessman CombiPlus. I was having significantly reduced water pressure on my hot water (the boiler was working well) which was making it difficult to have a shower. The local technician had never seen the problem before. He wasn't able to do anything for me on the first visit, but the next day he came back and I showed him this video and between the two of us, we were able to remove the heat exchanger and clean it. After that my hot water pressure was fantastic. I'm going to do this myself every year or so as a maintenance item. Thank you so much Allen! I live near the great lakes and we have very low mineral content in our water, but after six years there was enough build up that it significantly impacted pressure. At first it was intermittent and then it just kept getting worse. We saw no sludge when we cleaned it, just flakes of dark material. Interestingly, the part of the heat exchanger where the boiler water flows looked brand new and shiny.

TOP professional Allan! Another satisfied customer.

Great work and video Allen! Your ‘honest’ attitude goes a very long way. Readers and watchers, from a retired engineer, this man knows his stuff and would certainly gain my trust!

Great, informative, straight to the point video. This is really helpful, thanks so much! If I may add one small point, sometimes it may be good to do a second round of chemicals in the exchanger, as the chemicals loses it's potency and therefore it's ability to breakdown/dissolve the sludge/scale.

You are a super nice technician! Love your calm mood and doing much beyond what other average guys do! Thanks for the insights

I never comment on videos but just wanted to say, fantastic video that mate. Great work. 👍🏻

Enjoyed it, very professional sir.

Good video, Done like it should be. I use the Milwaukee 12v air compressor for charging the expansion vessel, cracking bit of kit and so much easier than a foot pump.

Hi Allen good vid as usual, not complaining about you saying the boiler was not serviced properly because you are correct in what you say, But when i went on viessmann course at their headquaters i remember the guy saying so they come with a 5 yr warranty so you do not have to take any thing apart and after 5 years tell them ( customer ) to get out vissmann. going to do this very same job that you have just done later this week, i hope it works out with the same result.

I see constantly this issue with the Vitodens combis. I find it surprising a premium boiler maker like Viessman still using rubber hoses. Early Vaillant Ecotecs had similar material links in their pipework, before being phased out/upgraded. This rubber hosing seems a perfect material for magnetite/sludge/grit to gather in. Could be worse, I remember seeing the 80/90s Saunier Duvals..😊

Great service by the way!

Great video alan very informative

Allen, great video, love the viessmann. that's practically a fully stripdown service. I usually remove the heat exchanger as well and give it a blast. Replace the hoses for either new ones or the copper replacement if possible. Anyway excellent work as usual sir. Keep us all on our toes to keep up with you ha ha

Great video as usual thanks for sharing 👍👍👍👍

nice job that was thorough

Great job and stay safe !

I had this problem with my Vokera, I removed the heat exchanger and gave it a good flush out but nothing much came out. In the end I fitted a new one and it cured the problem, unfortunately 3 years later the pressure in the system is now going up by itself; even with the feed pipe disconnected so it's looking like it may have a split inside the new heat exchanger now.

Hi Allen,Thank you for your video. I want to know something about my Worcester 24 CDI boiler. central heating is working fine . Before when i turn on hot water on tap boiler machain shows light on tap sign and light on fire sign but now it does not show light on tap sign on boiler and hot water is also gone. Near boiler there is small box with green light when it on hot water come up but for some time again green light goes off automatically. When hot water come then also there is no light on tap sign on boiler . Thank you

Hi Allen Great video a few queries regarding domestic use. I currently have a Viessmann 200 W installed with a Spira-Cross low loss header fitted, light industrial pump to add to the circulation but in just over 3 years I've ditched two heat exchange plates. I've spoken with the plumber regarding dirt separation but the header should take care of this, I've also mentioned the hard water within our area and possibly installing a water softener. Do you think this could help??

Amazing video, just what I needed! I

Was there a system filter installed with water treatment to prevent picking up in the first place, if not will you not be back in five year's or less time?

Perfect asistent boilers

Hi, I've got a Vitodens 050-w that was only fitted less than 2 years ago. Our shower keeps running hot and cold. When the shower is running, the flame comes on, ramps up, then goes out, on again, and so on. Doesn't seem to affect other taps in the house, just the shower. The boiler pressure was low, hovering just above 0bar so I've sorted that (thanks to your video!) but thats had no effect on the temperature issue of course. I'd like to have a rough idea of what the issue could be so I know I'm getting the right advice when someone comes and looks at it....thank you so much!

Nice job Allen do you replace the door seal and how does the condence trap come out thanks

Would Adey mc3 be a good choice for cleaning the heating side of the heat exchanger? Looking for advice.

Nice vid Allen just wanna say I believe they make the plates so u cant replace them back in the incorrect position. But in training they always say exactly what u said

Allen, would be easier and better to change rubber hoses, and put new ones on? Instead off trying to squeeze them to get the muck out. Trying to clean them is pot luck, you will never know if all the muck has come out. Love these types vids. Keep up the good work.

Hi Allen , love the content by the way, got a problem with the hot water on our boiler. Unless the heating has been on all day to the point where the house is like 23 degrees we don’t get hot water, it’s a vitodens 100 on the front of the boiler it has one dial. Which is for radiators. We never had an issue, untill we had the new boiler fitted it’s been frustrating for about a year. But the house gets far to hot, we set the thermostat to 21, if the hot water is switched on there is a switch in the cupboard where the tank is. The heating gets to 23 degrees or higher, even though it’s set to 21 on the thermostat. Any suggestions cheers

That was a cracking vid.

Great Work! What type of chemical did you use to clean the heat exchanger? Thank you!

Hi Alan - thanks for all the great videos did you only use the celaenr on the boiler side (not the cold water mains) of the plate heat exchanger? I have the smalle Viessman boiler and it's been great until about 3 months ago and now the hot water knocks and bangs / kettles I was told by the installers about 3 years ago not to use inhibitor in the system as Viessman have a stainless steel heta exchanger / burner - but if the plate exchanger is clogging up then this must mean the system has muck and debris in it... I am going to isolate the boiler / drain it then take the plate exchanger out (it's really easy on this model as its right at the front and a couple of screws) and then clean it as you suggest After replacing it would you suggest adding a cleaner & running the system for a few days followed by a full drain down and refill + inhibitor?

Good repair, I have the same job as you here in Spain, here the water is so hard that in some repairs it is impossible to clean the plate excharger, greetings from Spain.

Harika video .. Helal olsun size....

Hi Allen Thanks very much for these videos. I have this problem with my viessmann boiler it's the second time I've cleaned the plate heat exchanger and the pipes. Is there a solution to stopping this from happening again?

Nice to see stainless steel components that can be descaled with acid. Would proper power flush do this job instead, using FX2 for example? Rest of the system cleaned as well.

Hi Allen. Very good job mate. How do you know if the plate is good enough for unblocking/cleaning or it needs a replacing. Just trying to save some money for my future customers 👍

Prior to touching any part of the gas system .. did you do a soundness/drop... test and gas rate check To give yourself the base line figures ??

Allen, I have this exact tankless water heater. When we are trying to get hot water it get to temperature and then the boiler flame shuts off causing the water to run hot and cold hot and cold. Would this be the plate heat exchanger that is gunked up? My plumber recently did a flush of the system. And we are just waiting for gaskets to do the plate exchanger, if you were to guess would this be the culprit? Thank you for you video. You are very helpful. Take care.

Need advice. Living in south east Europe. Vitodens 100 W, boiler is 6 months in use, apartment is 40 m2, boiler brings hot water to the shower, and kitchen, pipes are less than 4 m long from the boiler to the faucet. Floor heating. While heating is on, I open hot water, use it normally, close it and when I want to use hot water after a minute or 5 min again, it takes 25-30 seconds for the warm water to arrive. Same thing in the bathroom and in the kitchen.So, example: I am having a shower, for the first rinse I wait for the hot water to come, ok. Than I turn the water off, scrub with soap for a minute or two, turn water on again and than I have to wait for 25-30 seconds for the warm and than hot water to arrive. And like that every time again waiting for the hot water. When the apartment heating is not on there is no problem. Is it the heat exchanger or a three way valve? Faucets are regular, nothing fancy, no thermostat. Please help. I would like to have some idea before i call the repair person.

Hi Allen, i have a biasi boiler m90e 24s, i was hoping you might know if the heat exchanger is at the back of the boiler and if it is easy enough to get out and also what descaler would you recommend if i can do this. Im an electrical engineer so quite mechanically minded, the only thing i dont want to do is mess with any gas pipes for obvious reasons...thanks very much in advance...👍🏼

Great vid, try pouring boiling water (CAREFULLY, it reacts explosively if you drip it onto the acid de-scaler!) into the clean ports of the plate heat exchanger, the results are immediate and obvious!, best to do it outdoors!.

Hi Allen Your help would be very much appreciated, especially with the weather forecast for this weekend. Our Viessmann Vitodens 100 was suffering with the symptom of the hot water coming in and out (not good in the shower), our plumber has replaced the plate heat exchanger (his first time working on a Viessmann) but when he came to turn the boiler back on it refuses to fire. The power is on and two orange lights come on the right hand side of the control panel and green on the left, but the display only shows the shape of a house with nothing else and no fault code. The fan & pump seem to be running. Have you ever experienced this as our plumber is at a loss? Hopefully you can help

When I do a plate H/Exchanger clean, I take it back to workshop and pressure washer both sides back and forward, you'd be surprised the amount of gunk that hides even after normal flushing. Also Always, always use eye protection when using that stuff. I hate rubber hoses on boilers, it's always a surprise to see this from German manufacturers. Good channel, I'll let you know shortly what I've found, what fits what, with press tools.

Hi Alan what kind of chemical do you use for cleaning the heat exchanger ? Kind regards Jim

hello. very nice video. thanks. I want to ask that on 11:22 , what is the name of the part you are opening it with a key, and I guess that some cleaning on that. is it necessary to take care of it?

Great job

Love the vid. What cleaner did you use and how long do you leave the cleaner in the heat exchanger itself?

Thanks for this great video. Insurance company said the exchanger is full of debris and they dont want to get a new one unless i pay although they have been servicing it for two years but never raised this ascan issue. Any ideas what i can do please? We are an elderly couple

Would a blocked heat exchanger cause issues with heating my radiators? My hot water takes about 30 seconds to start being hot, but my radiators are not warm at all they stay cold, the boiler sometimes shuts down with an F2 error

Hi Allen prob. Greenstar 28i junior mk 111 hot water takes a a longer period of time to get up to working temp. Q. Could this be the the plate exchanger be clogged or another prob any info would be welcome. Cheers.

Hi Alan. Do you need to replace the 4 seals on the heat ex with new or will they be fine to refit. (Asking for greenstar 30si

Great video! When the heat exchangers get blocked up do they need replacing?

I have a 050 Veissmann and had this problem. Veissmann engineer came out and replaced the heat exchanger, but warned me I needed a system flush. British Gas came and did it at a cost of £739, but did NOT flush out the exchanger, less than 6 months later, with a service in between the damn boilers giving me the F2 fault again. Should British Gas Have flushed out the exchanger after they did the flush?

Fab mate!! Great vid from start to finish. Is there a way to clean to Weissman heat exchanger without taking it out as a quick fix seeing as it’s winter and I wanna get it running again a bit better for now. I have one of those magnaclean things but it’s pretty damn clean and I guess that’s just to do with radiator heating not hot water. It’s not too bad but goes in waves like you show. Thanks anyway for your great vids. I’ve subscribed

Ive a plate which was bit green on one side. Can i easily test with compressed air for leak?

Have you any experience with intergas boilers? I'm tempted, I like the idea of no diverter valve, no secondary HEX, interchangeable parts across all models and an apparently indestructible main heat exchanger. Problem is no plumber I speak to has installed one or attended any problems with them. I hate combis and vowed I would go for a megaflow type system when the time came, but financially a swap to another combi makes more sense right now for me. Any thoughts appreciated! Three bed detached, doesn't take much heating, hot water use relatively low as just two of us here but we do like a good powerful shower.

Top video. Thanks

Thanks bro nice job

what descaler did you use Alan.? Good video. if it was installed correctly,system flushed, and serviced regularly,inhibitor added and checked,this should not happen.

Hi, I have vitodens 100 for about 12 years and I have problem with hot water running for a several seconds then cold for several seconds and so on. Is it a heat exchanger blocked?

What are the views of the rubber hoses? _Quality_ hoses on car radiators/heaters can last well over 20 years and 175,000 miles or so. They reach temperatures higher than domestic boilers. Latex radiator hoses just do not go wrong. More expensive but worth it.

top job sir

Hello, pls could you leave a name of that cleaning agent you used for cleaning the heatexchanger, also did you clean the whole boiler with this solution or just the pipes and exchanger? Meaning.. if you pumped up the whole system with this agent to clean it, or you just did those two parts and i was not necesary to chemicaly clean the rest. Thank you

Why does my hot water flow to my kitchen sink keep stopping unless I constantly increase the flow? It doesn't do it to my bathroom taps or my shower, Vaillant Turbomax, installed in kitchen.

Great video Allen. Could you explain where the brown gritty material in the plate exchanger may have come from? Thanks!

Hi mate, how long was you there in total ? What would you charge for a service like that. Other people offer "services " for 50/60 quid but it's obviously a quick telegan and they're out the door ?

Good video thanks. Just be careful to check the rubber grommets (100W) on each of the holes where the heat plate fit are still there before you refit it. Luckily I found mine had fallen out prior, you need to physically check with your hands as you are working blind, otherwise you may have a bit of a leak at the back.

Would love to know the best chemical to use on blocked Heat exchanger if you could please share what you used

Proper service would be take both heat exchangers out, put it on descaling pump for 15min each side and u have brand new boiler. Actually that's standard boiler service here in Croatia. But by the comments i can see u performed the miracle. Chemical cleaning of the boiler standard service 70€+ all new orings, washers and parts if needed.

Great video Allen how much would this service cost today…

ALLEN , WOULD YOU MAKE A LONG VIDEO ON BOILER SERVICING , PLEASE ? 🙏 . WHAT IS THE DIFFERENCE BETWEEN TANKLESS HEATER, TANK HEATER, BOILER AND GEEZER ?

I have had the same problem with a viessmann, had 3 new heat plate exchangers so far. Would i benefit from a powerflush? My radiators are getting hot which is good and so is my tap water but all 3 heat plate exchangers ive had have broken because of rust, sludge etc?

Great work Allen, what did you use to flush the hoses out? Or do you just replace them. Kind regards Rhyds

Hi Allen, do you cover WF10? I've got a similar problem of intermittent hot water. Thanks.

very interesting to watch how the boiler works. we have a problem with my boiler we have a viessmann engineer coming to check what is goin on?

Great video Alan, I have viessmann vitodens 050-w and when I set hot water on 40 degrees my boiler shows about 60 degrees, why is that? Thanks

Allen good video. What sort of money do you charge for doing that job?

l m from north africa lm colegue good job

I have no water coming out the hot tap, any ideas what the problem could be?

As well as the heat plate the flow switch on this and the 050 can model can impact the hot water performance

alan do 222f have plastic pipes inside

Hello Allan, I've got a Viessmann 200W 7248829 series, it's about 13 years old Origional Water Heating Pump, do you get problems with these, the Flow to all radiators is very Hot but the return on all radiators is cool, all radiators heat at top cold 1/2 way down, they say that the pump is been upgraded to a 7874668 thats now got a control circuit output to the KM Bus I presume to the main Control PCB (145 X4.1 & X4.2), I was thinking about getting the system flushed, it uses 10mm microbore plastic pipe, I be honest it's never been flushed in it's life, the usual addative has been used and air has always been removed from the system, I was thinking of changing the 2.4uf capacitor in the pump it's a rebadged Grunfos pump head with just the 230V AC mains feed, from that pump there is no KM control Bus whatsoever ! It's my own boiler, I'm wondering if you come across this Viessmann upgrade to their pumps using the Viessmann KM Bus on the 200W 35kW Combi Boilers? It's still a modified Grunfoss GHE Pump probably about 7meters of head.???

What’s the cleaning product for the plate heat exchanger?

Hi Allen. Do you put the crunchy hoses back with the original O rings or use new ones?

I was told Plate Heat Exchanger by every man and his dog when my hot water was only warm and the flow rate was very poor. I cleaned it and had a small result but nothing significant. Then I got a real plumber who knew what he was talking about and he diagnosed the issue accurately. My 'diverter valve' was at fault. It was changed and the results were dramatic. All of a sudden the boiler was operating like a new boiler again. Piping hot water with a very healthy flow rate.

Hi Alan, how much does a job like this cost, thanks

R u using knock out to clean the plate