JamesPa Posted February 10, 2023 Share Posted February 10, 2023 Im struggling with where (or whether) to put a UVC in my retrofit, because the existing cylinder is in the 'middle' of the house (on the first floor) and there is no obvious route for the vent pipe. One ASHP installer is suggesting that it is OK to pump the vent (pump being below the tundish) and thus take it out through the loft. I had the impression that the protection methods had to be 'passive' although in fairness the regulations don't actually specify this. I could see an argument that its OK provided that the pump is tested occasionally. The most likely fault scenario which disables the pump is electricity failure - in which case the heating to the UVC is also cut off so it 'fails safe' anyway. Has anyone come across a UVC with this protection method, or indeed any other method which does not involve a passive vent. Link to comment Share on other sites More sharing options...
PeterW Posted February 10, 2023 Share Posted February 10, 2023 If you mean the D2 discharge from the PRV then it has to be capable of taking significant flow at potentially greater than 95°C which means you need a specialist pump - they are about £600 and I think it’s @puntloos who has had to look at this for a basement solution. If you’re retrofitting anyway, take the floor up and put a 28mm copper pipe to the external wall as you’ll have around 12m to play with and unless you have a massive house this isn’t an issue usually Link to comment Share on other sites More sharing options...
puntloos Posted February 10, 2023 Share Posted February 10, 2023 56 minutes ago, PeterW said: If you mean the D2 discharge from the PRV then it has to be capable of taking significant flow at potentially greater than 95°C which means you need a specialist pump - they are about £600 and I think it’s @puntloos who has had to look at this for a basement solution. If you’re retrofitting anyway, take the floor up and put a 28mm copper pipe to the external wall as you’ll have around 12m to play with and unless you have a massive house this isn’t an issue usually Sorry not much to add here, I stopped my investigation when I ran up against the 'price wall' - but yes nobody was concerned with it being impossible to put a cylinder in a basement whih also depends on a bunch of pumps. Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 10, 2023 Share Posted February 10, 2023 Can you not get a waste pipe ( 32mm or 40mm ) to this location? Link to comment Share on other sites More sharing options...
JamesPa Posted February 11, 2023 Author Share Posted February 11, 2023 9 hours ago, Nickfromwales said: Can you not get a waste pipe ( 32mm or 40mm ) to this location? Not without significant disruption, otherwise I wouldn't have thought about pumping! Basically its a right mess whatever I try to do. Between this problem, the problem of getting quotes that are anything like half reasonable, and the nonsensical conditions imposed by my Local Planning Authority re noise if I don't go down the PD route (implying MCS and all the associated overhead), my retrofit of an ASHP is proving challenging to say the least. It seems to me that there are forces around deliberately trying to obstruct the mitigation of climate change, presumably because they fear that the necessary actions will somehow harm them in the short term and they don't care a fig about their children. I'm not blaming people for the problems finding a vent route, but the two other major obstructions are people-driven. I guess the alternative to unvented is vented; my current system is vented so replacing the cylinder with one that just has a larger coil does the trick. Of course that rules out the group of installers who refuse to use anything other than the pre plumbed unvented cylinder that ASHP suppliers usually offer. Altogether more than a little frustrating and depressing! Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 11, 2023 Share Posted February 11, 2023 33 minutes ago, JamesPa said: I guess the alternative to unvented is vented; my current system is vented so replacing the cylinder with one that just has a larger coil does the trick. Of course that rules out the group of installers who refuse to use anything other than the pre plumbed unvented cylinder that ASHP suppliers usually offer. The plug'n'play posse are everywhere. TBH it's deliciously simple from their PoV. Just rock up, install like your painting by numbers, get in van, leave. Why would they choose your job over the next plug'n'play one...... There are decent fitters out there and you just need to keep looking, which would be a very wise investment as your ( spare ) time is free, so to speak. My 2 cents is, accept the considerable disruption and get a 40mm waste pipe installed there, go unvented, and then you'll have no niggling worries about pump service / failure / replacement and repairs after damage etc, plus you'll have mains pressurised ( clean / potable quality ) DHW and kick-ass showers. The waste pipe can be done sympathetically by a separate plumber, whom you can work independently with to minimise disruption, and then the plug'n'play massive can do the 'easy' bit with their pre-plumbed 1st year apprentice ethos. Just check these learner drivers won't then have any issues with knowing the class / type of waste pipe used and what class / type of pipe it finally discharges into etc etc ( and they then refuse to G3 it / connect to the new waste pipe . You can just pump of course, still go pre-plumbed, and live with having to periodically purge the pump to see if it's still 'alive'. You can set a reminder to do that, and the G3 service, annually. Link to comment Share on other sites More sharing options...
Rich123 Posted February 11, 2023 Share Posted February 11, 2023 Are you talking the pressure relief valve drain. Sizing is required as building regulations . It should discharge in a safe location , visible. If you wanted to drain it via a tank or similar , you would need to fit an alarm with a visual display I would say. Installation of unvented cylinders is defined in the building regulations in detail under the domestic heating and hot water guide which you can download . also it needs a certified installer to sign it off. Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 11, 2023 Share Posted February 11, 2023 On 11/02/2023 at 11:36, Rich123 said: Are you talking the pressure relief valve drain. Sizing is required as building regulations . It should discharge in a safe location , visible. If you wanted to drain it via a tank or similar , you would need to fit an alarm with a visual display I would say. Installation of unvented cylinders is defined in the building regulations in detail under the domestic heating and hot water guide which you can download . also it needs a certified installer to sign it off. Visible tundish yes, but then can go into correctly rated ( suitable ) waste pipe for conveyance to the domestic FW network. Most installers do this via waterless traps which do not rely on water to maintain the seal. Link to comment Share on other sites More sharing options...
Onoff Posted February 19, 2023 Share Posted February 19, 2023 On 11/02/2023 at 09:53, Nickfromwales said: There are decent fitters out there and you just need to keep looking You can't beat BG. Look at the tidy job they did on my mum & dad's place: 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 19, 2023 Share Posted February 19, 2023 3 minutes ago, Onoff said: You can't beat BG. Look at the tidy job they did on my mum & dad's place: They did similar near me. They love the old / vulnerable clients the most. They only brought a short steps with them, and left 9m of unsupported gas pipe around the side of the house, which they only clipped at the start and the end of the run as they couldn't reach any more of it. They also converted to a combi boiler but failed to realise he was classed as infirm and that they had left him with a risk of scalding via the non-thermostatic shower he used off the bath taps. Absolute wankers. That gas pipe is shocking!! Right in front of an openable window FFS. Get the tossers back to sort it? Link to comment Share on other sites More sharing options...
Onoff Posted February 19, 2023 Share Posted February 19, 2023 17 minutes ago, Nickfromwales said: They did similar near me. They love the old / vulnerable clients the most. They only brought a short steps with them, and left 9m of unsupported gas pipe around the side of the house, which they only clipped at the start and the end of the run as they couldn't reach any more of it. They also converted to a combi boiler but failed to realise he was classed as infirm and that they had left him with a risk of scalding via the non-thermostatic shower he used off the bath taps. Absolute wankers. That gas pipe is shocking!! Right in front of an openable window FFS. Get the tossers back to sort it? The best bit it Dad was a BG pensioner, one of their own you might say. They took the header tank out and replaced with a small pressure vessel to make a sealed system. Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 19, 2023 Share Posted February 19, 2023 Looks like a potable vessel, vs a red heating one? Is it also completely supported by the pipework?! Link to comment Share on other sites More sharing options...
Onoff Posted February 19, 2023 Share Posted February 19, 2023 16 minutes ago, Nickfromwales said: Looks like a potable vessel, vs a red heating one? Is it also completely supported by the pipework?! Haven't looked closely, my brother sent it to me. It's on the CH. Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 19, 2023 Share Posted February 19, 2023 11 minutes ago, Onoff said: Haven't looked closely, my brother sent it to me. It's on the CH. I'm assuming there is a reason that potable are white and heating vessels are red...... I'm also assuming that clip manufacturers stay in business by plumbers buying clips from them and then using them Link to comment Share on other sites More sharing options...
Onoff Posted February 20, 2023 Share Posted February 20, 2023 (edited) Could that pipe be taken out through the gable end then empty into the car port gutter maybe? Then is that something I could do legitimately? Edited February 20, 2023 by Onoff Link to comment Share on other sites More sharing options...
Marvin Posted February 20, 2023 Share Posted February 20, 2023 17 hours ago, Onoff said: You can't beat BG. Look at the tidy job they did on my mum & dad's place: That's one of the worst I've seen! Have I led a sheltered life? Link to comment Share on other sites More sharing options...
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