steveoelliott

@John Carroll Also on the mixer taps pressuring the cylinder, there is a non return valve on the top.

@John Carroll I can confirm that labeled pipe is the EV outlet. When checked ~3 weeks ago the EV pressure was 1 bar and we increased it to 3 bar. I have another PRV on the cold mains set to 3 bar but with a cold tap running it's just under 2 bar. There certainly is no issue with backflow from mixer taps. The pressure generally from the hot taps is much better than it was prior and I suspect this may be due to the mesh being partly blocked / defective PRV. We know that was faulty as replacing it solved our issue. The bubble on the megaflo is knackered... I had deposits of it coming through taps, caught by the mesh on taps, hence the external EV. This was also confirmed by BAXI. I wonder if there is still any benefit going through the bubble recharge process even with a knackered baffle. I suspect not.

@John Carroll @JohnMo @ProDave Firstly @John Carroll, the EV is the other side of the combination valve. For the benefit of all that advised, this issue appears to now be resolved following the replacement of the PRV block. The one that was on the system was a Caleffi and not a genuine part (it worked fine for years) so I opted to swap with a very expensive set from Baxi which cost £204.00. My plumber did the work earlier today, cylinder was drained, he replaced the PRV with the new one and refilled. So far, no noise on tap opening. It got the point it was happening every time the hot tap was opened unless done very very slowly. One thing I noticed right away was how much more pressure there is when using the hot taps. It wasn't bad before, but now when opened, the pressure is much higher and it tails off after sometime. I actually remember it being like this a long time ago but hadn't notice it drop. With the old PRV block out, I decided to have a look at the mesh filter. It was impossible to pry it out and I had to force it out by ramming a screwdriver down the edge to lever it out. On one side of the mesh there were some crusty deposits so it could be that this was part of the problem or contributing to it. If a cylinder is serviced annually, I guess these filters are cleared but speaking to my plumber, very few people bother. I have another adjustable PRV by the main stockcock with gauge (this is also Caleffe), this provides a balanced cold. I may now with the knowledge from the other have this mesh cleaned or may just opt to swap it completely in case it leaks after being dismantled. Thanks all for your feedback.

Will do... I understand the potential problem but in the past when I have discharged the relief valve manually, this hasn't been a problem, but I appreciate it could be and also appreciate you highlighting something I never considered.

Yes I have one of these. Thanks for your analysis... 1) Whilst the EV is not connected to the output on the Calefe combination valve, it is (to my knowledge in the right place and doing it's job). It is notably not a genuine Baxi component. 2) The insulation is on my to-do list. 3) Discharge pipe from tundish, that's interesting as I wasn't aware of this but having said that when I have gone through the process of attempting to recharge the bubble in the past, it has worked fine with no problems. I appreciate it may not be to code though. The total length of the pipe is way longer than 9m as it goes from the loft, behind a stud wall, across a side / lean to extension and then outside. Having said that, when Baxi came out themselves to check the bubble, they never commented on this. The guy even went as far to say it was a good installation. The issue with the noise in the video now appears to happen EVERY time a hot tap is opened. It has got worse. I sent a video to Baxi and my plumber and both believe it to be a faulty PRV set. I am therefore pending a genuine Baxi one to arrive and my plumber will then fit it.

For completeness, attaching pictures of the installation. I have been told by my plumber and baxi the likely cause is the water inlet control block / PRV. I will be getting this changed shortly.

It’s a well known issues with Megaflos. If you google internal baffle failure, you’ll see it. The EV was at 1 bar when checked a couple of weeks ago and pumped up to 3 bar per instructions. It hadn’t failed at that point and the noise was present prior.

Around 60, not too hot. The tundish is dry. I check this every time I go in the loft as a matter of course. The bubble on mine has disintegrated, hence the external EV. A while ago Baxi came out to check and confirm the bubble was disintegrated and as part of this they checked the installation. They said it was fine. They no longer swap cylinders but offer to put a strainer on the hot side to catch debris, I declined as not had much of an issue with it and a strainer on the hot would just get blocked. I would be surprised if the relief valve was opening as bearing in mind this happens when a hot tap is opened after a heating cycle so pressure is effectively being relieved.

Hi, I have noticed that when a hot tap is opened for the first time after a heating cycle (in this case a bath tap), the water flows for a couple of seconds and then there is a very loud noise as can be heard in the video. Any ideas what it may be? The EV was recently checked and pressure increased from 1 to 3 bar per instructions but notably it did this before. I just at that time didn't know the trigger. It hasn't always done this however, probably the last couple of months or so. Thank you. Img 4357-1.mp4

Engineer from Grohe came and said this is perfectly normal. Apparently the way in which they shut off is instant and it isn't going to cause any problems. He took the static pressure as one of his checks, came back at 3 bar.

I contacted Grohe over the weekend, who have just now responded saying they will send somebody round to have a look at it. Guess it can't do any harm.

Yes, probably is water hammer but the pipe work is secure enough for it not to bang / knock. The question really is as to whether this matters? Presumably, this is putting strain on connections / joints etc. Pressure here is 2-3 Bar. Like you say, as the valve ages, it may change the behaviour. No expansion tank on the cold side, just on the hot for the unvented cylinder.

I could technically do A simply by slowing the flow in the valve in the toilet. There is a valve on the inside of the cistern. That said, if I have other taps running, you still get a thud, just less of one. Interesting idea re capped pipe, I have seen similar hammer arrestors that are made for this purpose.

Hi, I have purchased 2 x GROHE Flushing Cistern Solo 0.82 M 38691000 I am pleased with them for the most part and they replace existing Grohe cisterns that were in place for 14 years prior. However, these new ones appear to shut off the water supply very quickly after filling. Whilst the rapid shutoff does not cause our pipes to bang, I wonder if the abrupt shut off may cause issues further down the line. Is there a way to adjust the shut off so it does so more gradually? I have attached a video. Thanks in advance... IMG_4227.MP4

Not that it makes it correct / advisable but some of the lofts I've seen (even on modern new build houses with very thin trusses) very clearly overloaded and they've been OK. They would be built presumably with quite considerable margin. In one of my previous homes built ~1995, I had boarding which was suspended on lengths of CLS between the W trusses. They were screwed into which is a big no no. Goodness knows how much weight was up there but the boards and timbers alone would be ~300KG. It lasted the 10 years I was there with quite some weight up with no side effects. Would I do it now? No, but plenty of folks do.

They were using postcrete or something similar. I saw the yellow bags. I'll have to wait until I can actually get my hands on one at a later stage to check for movement at the base. Or when the contractors they are using are back to continue, I'll raise it with them and get them to show me.

Having now spoken with the site manager, I am a little concerned at the movement I saw on the posts when he was showing me all should be OK with the installation. I would expect almost zero movement to a concrete post, certainly my existing wooden ones are rock solid. However, with our existing fence in the way and no direct access to the site, I will need to wait until I can actually check them myself. This fence is coming to us at no cost but it's a long run and ultimately I am going to be taking responsibility for it going forward. I may consider trying to get a local fencing company to come out when it's done to give me a proper opinion and then I can challenge the developer.

That is part of the plan. Thanks for calling it out though.

Thanks. Perhaps I’m being a bit pedantic then. I’ve never tackled a fence but what I read suggested filling to the top. They got this last one how I would expect to see it.

Any feedback most welcome… I will raise this with the site manager. The thing is to remedy it now, they’d need to break up the existing concrete and start again. Anything new is surely not going to bind to the old.

Hi, There is a developer (I won't name) that is erecting a fence on our boundary and I believe that whilst the holes have been dug deep enough and the fence generally looks good, the filling of the holes has a lot to be desired. It's odd as to me, this is the easy bit, having done the hard work of digging the hole and setting the post. Perhaps I'm missing something but I'd love to canvas thoughts... I think the lack of support for the posts our side is going to cause problems and moreover the lack of concrete meeting the gravel boards in places will cause them to drop later. Thanks...

Seems to make sense to me... I know some would say rip the lot out and do it properly but that's a whole lot of upheaval for a shower that's used no more than 10 times a year.

I noticed whilst doing a deep clean on our en-suite shower today that the grout has seen better days. It's not flaking out but a couple of vertical runs have hairline cracks and other parts look a bit pitted. No tiles are actually moving / coming away but a couple along the bottom row sound hollow on the edges if knocked with my knuckle. The shower is seldom used, we tend to favor baths and have a much larger shower in the bathroom. It's probably been caught early. I know the grout is around 14 years old so it must be past it's serviceable life. The issue is the tiles are set on plasterboard walls and I suspect they are not hardeibacker style by virtue of the couple of slightly blown tiles. I am rather hoping that the grout can be removed and renewed with perhaps tending to the couple of slightly blown tiles at the bottom. However, when removing the old grout, of course further issues may surface. The other idea I had was to just to remove the shower cubicle and aqua-panel over the top. A bit of a bodge but it's seldom used. I just want to avoid the need to take all the tiles off, replace the plasterboard and re-tile. Perhaps I am being too optimistic.

I know your pain, happened to me when my membrane was replaced and the roofer just replaced membrane without checking falls etc. I was told that it's not a problem per se but I do have a minor leak now it seems so I will look to replace again and get the job properly.

Hi, I have standard white UPVC Double Glazed units, ~12 years old and owing to a new housing development, want to make one of these obscured from the outside. I was wondering if there are any suppliers that manufacturer mirrored / privacy glass UPVC units for the domestic / home user. I know one option would be to apply a film but I wanted something a little better. Thanks in advance...