Leaderboard

I've put UFH pipes through walls. Drill a hole large enough for some flexible conduit, make good with some motar....expanding foam.

So, to summarise this thread (and much of this MVHR forum area tbh): MVHR is a great enhancement to many homes that are reasonably well sealed -- the benefits can be great even for less airtight properties due to fresh air and significant humidity reduction, with all the associated benefits of those. There are rooms in many houses that don't have enough ventilation, or even any windows. So opening doors and windows aren't necessarily a solution, especially in winter. Don't buy expensive units and ducts unless you're chasing that last few watts here and there for very high performing properties. For retrofit, cheaper units and eBay are your friend. Use it how you want -- turn it off, up, or down whenever you feel like. But Passivhaus properties are designed around it so expect some consequences. Use windows and doors as you see fit - you have the flexibility. But probably don't turn the unit off with all the windows shut for extended duration. Make it smart if you can, or just ignore it and let it do its thing. Humidity is cheap and easy to measure and a good proxy for CO2 and other air quality issues. Right?

Gentlemen, speaking with my moderaters hat on, some posters are starting to directly insult others. Those posts have been removed. Please play nicely.

I have two second hand angle grinders of unknown make and hate them both. Watch out tor.... ON/Off switches that are near impossible to work or latch on when wearing gloves. Spring loaded locks you need to press to stop the disc rotating when undoing the nut. Nightmare trying to hold the grinder, hold the lock and work the spanner. This type of no tool quick release nut is great and fit most makes..

I too ran pipes through walls for the same reason to stop congestion in doorways, drill hole and put short lengths of overflow pipe in then thread the UFH pipe through that, 👍

Zoot the Hoot. Having read some of the posts here are my thoughts. You are going to have to accept some stuff. You don't understand a lot of the technical stuff. Neither do i. You talk too much, and in riddles. I talk too much. My thoughts are that you have Three options. 1. Accept what you are being told by valliant. 2. Tell them to bugger off. 3. This is what i would do..... When the bloke comes around to do all your heat loss calcs, rad sizing, equipment requirements etc. Ask him if he could spare you 15 mins. Make him a cuppa, and press £20 into his hand. Forget all the crap that has gone on before, nobody will be interested in hearing that. I usually start with. "I'm as thick as shit when it comes to ASHP. Can you talk me through what you are going to do, and try to explain it to me as if i was a 10 year old. Then shut the f up and let him have his 15mins. At the end you are permitted to ask him to clarify a couple of things if necessary. These questions should relate to how to operate the system, to get the best out of it. Not questioning why he is fitting that, or not fitting this. He is the designer, not you. You have to have some trust in people who know better than you. (i stuggle with that, but thats life. Then let them get on with it. Remember, It ain't gonna be any worse than what you have already. Best of luck bud.

At last somebody has suggested this. I never fully understood the logic of combining ufh with radiators that need a higher flow temperature given that there is no good way, with a boiler or a hp, to achieve two different flow temps simultaneously. Of course I realise that it's the pragmatic solution in some retrofit scenarios, but I can't see how it makes sense in a new build.

Not really that necessary for 100mm centres if well insulated, I am running 300mm centres, max required flow temp is 35 at -9 outside. Really if you match the rad size and the floor centres so they all have the same flow temp on paper, you can then balance the flow rates to get the room temps where you need them. Then you are running at the lowest flow temp. Then you start questioning the need for any mixers or additional pumps.

Took a few days off to just do......feck all. It was awesome.

In cold weather, the outside unit of an ASHP can ice up. When this happens it needs to be defrosted. To do this, the system reverses for a short time and actually removes heat from the water in the system in the house to warm up and defrost the outside unit. It requires a certain amount of water in the heating system to do this, otherwise it would cool that water down too much during defrost. Some ASHP's have a backup electric heating element. Those that do, can turn that on while it is defrosting, so some of the heat to defrost comes from that and less from the water in the heating pipes, so less water volume is needed.

Isn’t one of the issues that the concrete has steel reinforcing bars that rust due to leaky roofs (as it was commonly used to span wide flat roofs) and over time this has failed? I have Mannok foundation blocks too. I doubt I’ll see another 30 years so it will be someone else’s problem 😂

From what I've seen, most of the buildings affected area public ones built fast and cheap.. Yet another example of signing off poor working practices in the name of cost cutting. They knew threse buildings were crumbling years ago, but kicked the cost of repairing them down the road until the next election..

It's a different risk to asbestos, it won't kill you by poisoning you. The problem with raac, used for example for ceilings, is it's strength seems to decline and it might collapse without warning. I don't see that risk with your blocks.

Don't worry 😜

I use the Chinese method to avoid PPE.. Jokes aside, the position on the cutting blade you make contact with and the relative force will define the direction of the debris. With practice, you can guide most of the sparks/dust in the right direction.

Yes and ear defenders, those diamond discs “sing” loudly.

I would concider corded as well. Personally if I'm using angle grinder I do a lot with it. Corded are really powerful last as long as you mains or a generator kicking about. I also prefer a fixed speed,with a sliding on or off switch. It all depends on what handed you are, you will hold the angle grinder differently. Don't try to force your self to do it wrong, it will end up hurting you. Also safety glasses are a must, anyone why says otherwise ignore them. Been to A&E several time after doing a quick job and getting stuff in my eyes.

Good luck in your endeavours

If your hubby is an electrician then he just needs a roofer to help with the roof work and DIY is straight forward. Buy or borrow a used scaffold tower and flog it afterwards. You'll likely pick up a 4.5kw kit(excl battery) for under £3k and the parts for much less if you are prepared to wait and buy as things as they come up on ebay

The wattage will increase the torque for any given RPM. The size of the cutting disk will have a maximum RPM. This is why larger, more powerful, angle grinders can often have a lower RPM. Pi x diameter x RPM gives you the equivalent linear cutting speed. I prefer toggle switches, and a speed controller. Can't think that I have seen both together in recent years, so go toggle switch if you don't have a choice. Once switched on, you can use use both hands on the grinder to control it. Or one handed if needed. Really try not to over think it too much. Sooner or later you will need to just switch it on and plunge that disk into the wall. It is not the backwards and forwards motion that will catch you out, more twisting the cutter in a slot, that is when it jambs up. If you can, try cutting up an old brick, concrete slab or large stone, get a feel for it.

I bought a cheapie from screwfix, has soft start and never let me down, if your going to use it DIY rather than pro I would recommend it https://www.screwfix.com/p/mac-allister-msag2000-2000w-9-electric-angle-grinder-220-240v/522gf left to right otherwise it will grab and throw it out. I would opt for trigger in case it gets away from you.

Just get some cheap 125mm diameter ones. They will do the job just fine. Make sure whichever angle grinder you get has the larger spindle. My little one is only 10mm diameter, that limits the size of disks that can be fitted.

I don't believe it is faulty, I just believe it is not up to your exacting standard re noise, and not adequate for the high heat demand of your particular house.

Would it cheaper to run the immersion on a Sunday morning to charge the cylinder to higher temp - more capacity sorted. I am assuming your on a heat pump?

There’s no point in pointing this out to @zoothorn, he’ll just question if you have direct experience of a vaillant buffer tank and if not, say you’re unqualified to advise him.

The biggest thing is the UVC which (depending on size) which will be heavy being full of water, the rest won’t be a problem but your SE will give a definitive answer.

Agree, yet the topic was started and is actively being discussed/debated. I suppose the best answer that everyone has is to install first and see how it goes from there.

@zoothorn I answered this back on page 2, and again on page 3 when you typed it out in all caps. Maybe I should have typed the response in all caps? With the above picture it is clear. The hydraulic module contains the backup heater, so your current system requires a smaller system volume. Ask them why they aren't fitting the backup heater with the new system. It will cost more to run than a buffer, which may be the reason. If they are, ask to see their system volume calculations and post them here. If you repeat again that nobody has answered this question I highly doubt you'll get any more replies.

I think you might be the architect of your own downfall here. The installer might have concluded there is insufficient system volume based on your reports of noisy defrost. The original installer might have calculated there was enough system volume based on the assumption the user wasn't surreptitiously turning radiators off. Hence no buffer or volumiser needed. The new installer would look at the system on his visit and think "hummm... there should be enough volume according to the calculations and my inspections yet the defrost is still behaving like there isn't enough.... There must be something we are missing, best be cautious and stick a big buffer in to make absolutely sure we won't have this problem again!" If you insist on operating the system in a way it's not supposed to be, it's not surprising it misbehaves and if you don't tell the installers you have been doing that, it's unsurprising they struggle to rectify the issues.

I am currently on site sampling it and will report back here.

I would temper that with, a remark on noise and overall reliability. Also support and spares if things aren't quite right. I bought my units from eBay but expensive units for super cheap prices. One unit had an issue, got great support from Titon and had the spares in two days. Set it up per building regs then once signed off, used the setback setting, which knocks fan speed down to between min speed and current speed setting. Rarely use boost, totally silent, zero drafts, monitor CO2 in master bedroom and lounge - zero issues. Runs 24/7, nothing smart, manual boost switches. Complex controls if you like, but no need.

Then let them come and fit the monoblock, with a buffer tank if they insist. Give it a fair chance and only then discuss any new problems that come with the new system. Rejecting it because you think there might be a problem is not valid reason for rejecting it.

@ToughButterCup have you ever lived in a property which has MVHR? No one else I know has anything like I do, and their houses are stuffy to me, but you don’t realise until you’ve had MVHR. maybe you open windows/doors more than you would if you had it, I don’t open much up year round, unless I’m out in the garden. And if you’ve ever seen a used MVHR filter, surely you don’t want all that crap over carpets, furniture and in your lungs? for me MVHR chips away at humidity like nothing else I’ve ever experienced, and the house smells fresh all year round, I deal with exterior smells with a carbon filter which works brilliantly. And the unit itself, cost me £400 off eBay brand new, plus another £150 for the upgrade to Hepa filters and carbon, the pipes you already have in place so maybe just keep an eye out? honestly can’t think you’ll ever regret it, just fit and forget for the sake of around 40W of power or less

I have never liked E7 because it penalises you with a higher rate for the daytime. And that then forces you to use the noisy things like washing machine, dishwasher, tumble dryer etc in the middle of the night when you want the house to be quiet. Far better is a single rate tariff, and solar PV, then the best time to heat the house is in the daytime. using a heat pump.

Air separator probably piped up with a cold feed and a vent pipe - will be a gravity system no doubt that has been converted in the past and prone to sucking in air.

When we were seeing potential sparks, one asked about wall construction. When we mentioned the services void, his eyes lit up. I think that this showed not only that he would have that facility, but also that we knew what we were doing. His sensible quote followed and we are all happy.

I always used a 9” grinder, make sure it’s got “soft start”, although big you have more leverage over where it’s going. You will have to stand on something solid (no balancing act). With my diamond disc only one cut required to slot the lead in and wedge tight. I always used lead seal as you linked too.

The best approach woukd be to "suck it and see" Install it and see how much the sound bounces about. Having worked with noise attenuation (from roads and industrial sites) itvs really tricky. Sometimes barriers can make things worse! It may be the noise is perfectly acceptable with no barrier, then the issue is simply visual.

Great news you’re doing your due diligence on this I did the same. Surely this percolation test failure is a point of negotiation as it will be the same for anyone else interested in buying the plot if you didn’t. Therefore I’d making it a condition of sale that they grant a wayleave as a minimum as part of the purchase. I’d also be talking to them about how to solve the problem for both you and them by coming to some financial agreement on splitting the cost. As it’s an estate do they have access to diggers etc? Reed beds are very difficult to keep from everything I’ve read and prone to failure.

I slated our first one with Spanish and made the mistake of thinking grade a1 give you a top quality slate It doesn’t It relates to the piro We returned about a 1000 twisted slate Had we used a roofer they would have been throw off the roof This time we were less trusting and Used 600x300 Estilo prime Same grade but a very flare slate with hardly any twists 5-7 mil While it took myself and my wife nearly six week to slate the house and workshop It was far easier than previous on a more complex roof

We used egger protect, with their glue [Foaming, Similar to Gorilla Glue, and surprisingly cheaper !!] Just looked at the photos, and we were 2 months between fitting and having the roof on, with no problems.

You could borrow mine for a couple of weeks. It would help me with procrastination points on the house not finished thread... I will need it back because the house is really bad for co2 and heat build up when we work in there and there isn't a good through draft.

Octopus Energy has sent shockwaves through the UK renewables industry. The company has announced that it will accept solar installations onto its Smart Export Guarantee tariffs without MCS accreditation. This represents a significant development for electricians and homeowners, as they can now sell their excess energy back to the grid at a very competitive rate.

I frequently come across burned out switches. The usual culprits are 20A switches or worse, FCU's used to switch an immersion heater. One I did recently the switch had burned out to the point of making a black hole in the front plate and inside the mechanism had completely crumbled to bits, but the plastic back box it was in was not even charred. I suppose this is what we must expect of the organisation that decided the "solution" to CU fires was to put the CU in a steel box. I always argued the solution should have been to take a long hard look at WHY CU fires happen and try to improve design, like go back to the old fashioned idea of 2 screws on all terminals, and mandate that if you are going to use cage clamp terminals, you design them such that it is physically impossible to put the busbar finger the wrong side of the cage clamp. But no, we have not changed the design to stop a fire, just done something to try and contain it. And soon you will have to fit one of these expensive devices to detect the fault. What is the betting these AFDD devices will still have a cage clamp terminal that has nothing to stop you inserting the cable or busbar on the wrong side?

The ones Bimble Solar are selling, used panels described as having damage to the backing sheet, though of the 25 only 3 show any signs of damage and it is very minor indeed. If I must use android if that is the only platform the "right" software is on then I will, but I am too much of a dinosaur and prefer my computers to have a decent size screen, a proper keyboard (not a touch screen thing that takes up half the already minute screen) and a proper mouse.