steveoelliott

A small bedroom / office. They don’t sell this one now but do similar ones.

If I am being unreasonably picky. Please just tell me. I have broad shoulders.

The noise isn’t a major concern. But something that I did indeed notice however that can’t be controlled by installation 🙂 in terms of shrinkage this was paste the wall.

Hi Folks, I purchased a mural from Photowall and had our decorator hang it for us. Unfortunately after he left and I took a look, I immediately noticed gaps / lines along the edges of the paper. I figured I'd give it 48 hours to dry / settle but it's still the same. I raised this with Photowall and they told me 95% of their customers have flawless results and that this must be down to the installation. Not sure I buy this yet. Anyway, I do intend to flag this to our decorator but there isn't anything he can really do now it's up. I am just more curious as to whether I need to consider somebody else to hang any future murals or paper. He has been very good on the two jobs he has done so far and proclaimed to really enjoy and excel at hanging paper. What I don't want to do it be overly picky or critical of anybody. One other observation is how the paper sits on the skirting. Rather than being uniform on each strip, some of it steps out marginally. Having never papered, I'm not sure if this is normal of me being pedantic / unrealistic. Appreciate your thoughts and insights. It's certainly not bad enough for me to want to strip it and redo but it's irritating when you know it's there.

Coming back to my original issue, I even got the noise (previously) with the cold inlet to the Megaflo shut off after a reheat. Now I guess there would be pressure in the small piece of pipe between the cold inlet closed but I would be surprised if this caused the issue. I measured the water temperature at the tap which is some distance from the tank and it measured 57.5 with the tank thermostat set to whisker above 3. I debated dialing the temperature down a little to see if that stops it but one has to be careful of legionnaires. I haven't lowered the EV pressure to 1.8 bar yet, it's something I intend to do when back from a business trip. Playing with it just before I go and leave my wife here isn't something I'm keen on doing as at least I can keep an eye if here. Mind you it was set at 2.8 bar back in January so I suspect it will be decreasing slowly anyway I had wondered if the layout of the pipework from EV may cause issues like this to occur or be worse.

@John Carroll I didn't play with it whilst the gauge was compromised, I will need to do this with a gauge on the outside tap again. @Nickfromwales Not sure if the gauge was pre-installed or my plumber put this on the PRV. I know the new cap thread was put on using liquid PTFE. That said, the leak was definitely internal to the gauge. That green staining behind the O ring was never wet and I suspect it may have been the result of condensation as I've seen it on these pipes before when cold water comes in.

The gauge was removed today by my plumber and capped off. As you can see there was some corrosion internally and I think eventually this may have caused some issues.

Interestingly I got a response from the manufacturer stating that the gauge on the PRV should only be connected when setting the PRV and then capped. They said that constant exposure will inevitably lead to corrosion of the bourdon tube and lead to leaks.

@Alan Ambrose @John Carroll Thanks for the feedback. The valve in this case is just part of the PRV but it can be easily capped off. I noticed this morning that the water has dribbled out the front of the gauge but there doesn't appear to be any new water. Something must have triggered this weep or it could even be condensation. My plumber is supposed to be coming to cap it or swap it.

Thank you. I probably will avoid using gauges permanently for this reason. The outside tap one is a great idea and I hadn’t considered them having a check valve on them.

Thanks. About 10 -12 metres to street. It’s 15mm pipe incoming. When I measured the static pressure at the outside tap, which is the other side of the house that was matching what was on this gauge though. I’ve asked my plumber to replace / cap off that gauge this week. In the interim, I am checking it regularly as I am concerned about it peeing our water everywhere but this is a new and separate issue.

And of course replace the gauge next week @John Carroll. I know previously you’ve said about installing gauges at multiple locations but the risk of this happening to them and potentially leaking is a concern for me.

It happens after a reheat if it’s going to happen, but then doesn’t always. here is a picture of the PRV. I am concerned there is water in a gauge which I’ve just noticed. Good advice re setting the PRV. I will try that.

Outside tap is downstream. Problem is I believe the outside tap has an NRV so you never see a pressure drop. I’ll try and find model of PRV.

Interestingly, I thought of this. I took the pressure from an outside tap or one of those screw on things you get from Amazon that was also 4 bar. PRV main is caleffi and the uvc Baxi.

It reads 4 bar almost immediately after shutting tap off and stays there. Might be a bit more or less depending on time of day etc. it never really creeps up. It is a large 5 bed house with lots of outlets / 4 bathrooms so a big system to flow around.

Thanks. What’s the correct way to set the PRV though. With a tap open? And should I aim for static pressure at 2 bar? I think the issue is the static pressure at 4 bar despite it dropping to 2 bar static when tap open.

Yes the stop cock PRV is on the main and prior to the UVC PRV. It seems to be the rapid discharge from the EV that triggers this.

One at the main and one on UVC. It’s this that gives the balanced cold. They offered a UVC but I took the option of a boiler instead as I planned not to use a megaflo going forward to opt for another cylinder. The thing is I want to be certain it is the cylinder before swapping. Are you able to advise how I set the dynamic pressure on the PRV off the stop cock. Is it just open one outlet and set? The static is around 4 bar and between 1.8 and 2 bar when running. thanks again.

@Nickfromwales and @Mattg4321 - The PRV on the megaflow is fixed at 3 Bar (no adjustment on the BAXI one). However, the one on the incoming cold main is adjustable. Question is mine does not have a setting with pressures, rather you adjust it with water running and use the gauge. To find dynamic pressure, I figured this would be with one tap open but wondered what is the correct way to measure dynamic pressure. I read elsewhere that this noise is caused by the sudden rush of flow when you open a hot outlet propelled by the charge of the diaphragm in the vessel. In an ideal world we'd have a valve that allows water to fill the EV unencumbered but restricts it emptying. Not sure if such a valve exists.

This is a really good example of the problem but not my video.

Thanks @Mattg4321 my main concern was actually damaged or rupturing of pipe joints due to the vibration. in terms of what you did with your PRV, did you open a tap and then set the dynamic pressure to 2.5? In my case static is around 4 bar dropping to around 2 bar with a tap open. The more taps I open the lower dynamic goes naturally.

I’m also interested in the theory that the PRV should be set to the incoming mains pressure or marginally below but whether this means the static or dynamic pressure.

@Mattg4321 Thanks. Did you set the PRV for the cold main based on static or dynamic pressure? Also did you look at my post / watch the videos. Interested to see if what you saw was similar.

@Mattg4321 Did you ever get to the bottom of this issue? Was lowering the pressure to 1.5 bar your ultimate solution? I have an ongoing issue, not yet resolved here: The latest I've gathered is that EV pressure should be ~0.2 bar lower than dynamic pressure. But what is an accurate way to measure it. We are fortunate to have a gauge on the PRV at the stop cock. Is just opening up a tap enough to measure pressure? The thing is the pressure shown on the gauge will vary depending on the tap used / flow rate etc.