jack

Thanks @Nickfromwales No point replacing the elbow if the waste outlet turns out to be the problem. I'm flat out today but I'll take a look when I can.

Thanks @Nickfromwales This is the joint: https://mcalpineplumbing.com/plastic-chrome-fittings/multifit-waste-fittings/135-universal-bend-x-bsp-coupling-nut/ The end that's leaking is the BSP joint at the waste outlet. I'll take it apart again later and check more closely for damage at the waste (the elbow itself looked fine). All I noticed when I first took everything apart was a short bit of thread missing at the lead-in end of the threaded waste outlet.

We've had a leak underneath an upstairs shower for a while now. I've finally gotten around to opening up the ceiling underneath and having a look. There's a 135 deg, 1 1/2" BSP to 40 mm compression elbow coming straight off the 1 1/2" BSP outlet from the shower waste. Based on the muck around it and how clean everything else was, it's clear that's the source of the leak. The BSP nut was very loose - I had to turn it nearly two turns to tighten it up. I hand tightened it up as firmly as I could and tested: immediate leak. Dismantled and pulled out hair, gunk, etc from the shower waste outlet, then cleaned up the fitting and connections as best I could. Installed again, firmly hand-tightened everything, tested: immediate leak at BSP joint. What would be your next step? My first thought is that the rubber washer's hardened over time, so replace that and see what happens. Anything else to look out for? Should I go for the same square section washer? @Nickfromwales, tagging you in for visibility. Thanks.

I bought a cheap Erbauer one in mid 2015. I've told the long story before, but the short version is that the window installers massively stuffed up by not packing the windows up by 15 mm as shown in the drawings. When they went to install the cills, the outer edge of the reveal held the cill up almost horizontal. I bought an Erbauer oscillating tool and some blades, and spent hours - maybe a day more - trimming the reveals to allow the required fall. (Upon reflection, there was probably a more efficient way of doing this, but nothing else occurred to us at the time). By halfway through, the grease in the gearbox had liquified and leaked out everywhere. It got louder and louder, and the vibrations were horrible, but it kept going and got the job done. I've used in many time since and it still keeps going. I actually had it out on the weekend to move a smoke alarm in the kitchen, by going in through the floor above. Still produces insane amounts of noise and vibration, but other than that works perfectly well for the sorts of things I need it for. I'll use it until it dies.

Not a realistic option at the moment, but: https://en.wikipedia.org/wiki/Atomic_battery

100% agree.

I'm more than happy to have turbines near me. I've had plenty of conversations with friends who feel the same. More to the point though, building more in England is unlikely to change the number being built in Scotland. If you think there are too many wind turbines being built in Scotland, that's something to take up with the Scottish government.

https://www.instagram.com/reels/DOd5v_yiL4E/

Fixing it in the open position will guarantee to make your house hotter during the day. Bypass should only be used (and should automatically turn on) when the outside temp is below the inside temp. Your MVHR shouldn't ever be delivering 31 deg air. In normal, non-bypass mode, the MVHR will work to maintain any existing temperature difference between inside and outside. In summer that means it will transfer most of the heat from the incoming air to the outgoing air, significantly reducing the temperature of the air delivered to the house. So if it's 30 deg outside, and 20 deg inside, the air delivered into the house will be something like 22 deg, depending on the heat recovery efficiency of your unit. Summer bypass only comes on when it's cooler outside than inside. Depending on the unit, you might be able to adjust the temperature at which it kicks in. To maximise effectiveness: Reduce airflow when it's really hot outside, cooler inside, and you want to minimise incoming heat. Turn it off if you like, but you risk a stuffy, humid house. Personally I'd avoid that. Summer bypass won't operate in these conditions. When the temperature outside drops below the inside temp and summer bypass kicks in, bump up the flow rate to maximise purging.

I've deleted the duplicate post.

Any particular reason to place this upstream of the MVHR unit? I may be missing something, but this way you'd lose some of the "coolth" through heat exchanger inefficiency. That inefficiency could potentially be worsened by moisture in the outgoing air condensing due to the cold incoming air.

Generally yes, but only if humidity is lower outside than in. Where I am, humidity is still high, and is forecast to rise through the night into the high 80s. Thankfully it should drop a fair bit through tomorrow.

I lowered the flow temp on our underfloor cooling from 16 deg to 14 deg a few days ago, in anticipation of the several day heat wave. The surface of the door (polished concrete) slowly fell to a minimum of 18.7 deg a couple of days ago. It's slowly drifted up to 18.9 deg since. In the middle of the afternoon today, I noticed some darker spots on the surface of the concrete. Within three hours of noticing that, entire sections of the floor in the kitchen were slightly damp. We've never seen so much as a whiff of moisture in 7 or 8 years of using underfloor cooling. It's amazing what a two degree flow temperature difference coupled with high humidity (~80 inside at the moment!) can do. I've turned the flow temp back up and will monitor.

You need some ventilation even when everything is closed up. Draughts will do it if have a draughty house. MVHR is a way of providing that ventilation without bringing in full temp air from outside to replace your precious cool air. As noted, MVHR isn't 100% efficient. I tend to keep it turned on as low as possible during weather like this, as that reduces the losses in absolute terms (i.e., you lose double the amount of energy with the same 90% efficiency if you double to airflow).

How so? All MVHR does is try to maintain any temperature difference between inside and outside. If it's cooler inside than out on a hot day, then MVHR will help. Or are you thinking about how MVHR would (or wouldn't!) work in your draughty house?