Do I need a Pressure relief valve

[natlol]

Hello all I really need some advice.

Had a plumber replace my bathroom last August and he fitted a Hansgrohe Marin Centostat Bath/Shower/Mixer. Since it was fitted when you have the temperature between hot and cold it makes a high pitched whistleing noise. You can stop this by gripping the adjustment and putting pressure on it with your hand. It also stops if you turn the tap to fully hot or fully cold.

If i flush the toilet or turn on the cold tap on the basin it also seems to stop.

The hot is fitted to a combi boiler and the cold straight to the main. In the picture in the manual it shows a pressure reducing valve fitted after the stop tap which I dont have.

Do you think fitting the Pressure Reducing Valve will stop the noise. The plumber doesnt know what to do and told me to ring Hansgrohe but they have said that they will charge me £100 if it is not the tap and the installation?

If i have to have a PRV can you recommend one please?

Many Thanks

 

[cider]

Dont think your plumber is going to win any awards for iniative!
Need to do a pressure test and see if it is within the manufactures spec.
If the pressure is too high!!!!!!
If not and the shower is installed as per instructions then get the manufacture around.

 

[natlol]

Yeah I know...he says that he hasnt got one of the gauges to do the test so I am starting to loose faith. I seem to be doing all the leg work. The manual does clearly show a PRV fitted after the stop tap in our setup. I suppose I have to fit one regardless of if it sorts it out as they will just use it as an excuse not to repair under warranty.

 

[cider]

did he supply / spec the shower? if he did get him to get his lazy ass round and sort it out. test kits are less then 20 notes or he could make one for less.
If he doesnt want to come back give him some bull about another big job you plan to if he is as thick as he seems he'll probably fall for it

 

[ChrisR]

he says that he hasnt got one of the gauges to do the test

£10.80 in my local boutique.

 

[Agile]

I really do not understand how some of these nupties get any work!

If he is fitting a shower mixed then its his responsibility to ensue that he is fitting it correctly.

Part of that preparation is to measure the water supply pressure to ensure that it does not exceed the manufacturers specifications.

He is not equipped to do his job!

I suggest that you ask him to purchase one as he has not properly tested your installation and operating at excessive pressure may even damage the shower. You could tell him that you will hold him responsible as he failed to measure the pressure before fitting the shower.

Tony

 

[natlol]

Hello all...because of the problems with the plumber..I brought the pressure tester myself and it is telling me that the cold mains pressure is a shade under 5 bar. In the manual for the tap it says a prv should be fitted if pressure is over 3 bar.

Should i fit the prv on just the cold side before the tap so that it doesnt affect the hot water (combi) or should i just fit it to at the start so it covers the hot and cold water?

Also...can these prvs be installed veritcally and horizontally?

cheers

 

[leakydave]

Simple: put the PRV where the manufacturers tells you to.

It's a shame that there are plumbers like your numpty installer who just fit the shower and Foxtrot Oscar without looking at the MI and using the correct tools.

[I draw the line mind you at £30 for a weir gauge... I fill a marked bucked for 30 seconds and go from there...]

 

[natlol]

It doesnt actually say anywhere in the manual that came with the tap that a prv should be fitted. I just noticed that in the diagram of my setup it has one after the stop tap.

It says about a prv being fitted on anything over 3 bar in the updated manual which I downloaded online as i couldnt find mine originally.

The specs for the tap are

operating pressure max 10bar
recommended pressure 0.2 - 5bar
Test pressure 16bar
Hot water temp max 80 degrees c

My cold water pressure is a shade under 5 bar so I guess I am within the limits on the cold and where the water goes through the boiler it is also gonna be less.

I cant test the hot water pressure at moment as i havent got a fitting to connect it on as i used the washing machine filler to plug into but i dont have one on the hot.

Would the combi drastically reduce the pressure causing an imbalance between the hot and cold?

I didnt really want to reduce the pressure on the combi if i can help it.

 

[Agile]

Be aware that in Germany where your shower unit is made the plumbers will be highly qualified peope with all the required equipment. The instructions would be written from that perspective!

The instructions are really a little inconsistent saying its OK at 5 Bar but asking for a 3 bar PRV.

However, I suppose the Germans would say thats totally correct for a well designed system with proper safe operating parameters!

If you fit a PRV then that should be in the whole system and not just in the cold.

If your flow rate is good then consider a one size larger PRV, that is a 22 mm on a 15 mm supply pipe as the flow characteristics are not perfect.

The combi probably already has a simple flow rate regulator.

Tony

 

[natlol]

Just wanted to post and thank everyone for their kind help.

We have sorted out our screaming tap by fitting a pressure relief valve after the cold main. This has stopped the tap screaming and has dropped the pressure to 3 bar.

Unfortunately we have lost a little flow from the taps, and the valve isnt the quietist, but at least the the tap isnt screaming anymore.

Thanks so much for the help it had been driving us potty.