Replace pressure relief / reducing valve cartridge

[mr-burns]

Hi,

Essentially my question is: "Can I replace the cartridges on pressure reducing and pressure relief valves?" Here is my reasoning as to what the problem is:

My girlfriends flat in Bow, London. Megaflo direct HW system, and water is running through the tundish. I tried the 'replace air bubble' trick, which didn't stop it, so I tried to work out what it could be. The water in the cylinder is hot, but the water running through the tundish is cold, so it isn't related to the HW temp/press relief valve.

There is a drain pipe from the mains cold inlet control system which also runs to the tundish so I'm pretty sure that this is the problem.

Where the mains water comes in (just after the stopcock), it first goes through what appears to be (from picture search on their website) a Reliance RWC-SYR 312 series (312F I think) pressure reducing valve (it has 3 bar written on top of the black bit) and then into a RWC core manifold 8 bar pressure relief valve (looks like one of the two at the bottom of this page)

That same website has replacement cartridges for the reducing valve for £20/£30 (depending on size) and the relief valve for £7 - this would be a hell of a lot cheaper that getting a plumber round to sort it even if I don't identify which one is as fault and just do both.

I have done a fair bit of diy plumbing before, but am not sure as to how to replace these cartridges, or the regulations (I know there are some about pressurised HW systems). The little blue cartridge on the 8 bar relief valve has an anticlockwise arrow on it which I first thought about turning to see if it would maybe clear limescale or something, but now am glad I didn't as I can just see the cartridge pinging out and me getting covered in a LOT of water! The other small complication is that the pressure reducing valve is installed with the black catrtidge facing a wall, so I guess I would have to undo the nuts and rotate the whole thing 90deg to be able to remove the cartridge?

So, should I do this myself, or get a plumber?

Many thanks

Rob

 

[Hysteresis]

I have replaced the cartridge in my RWC pressure regulator, but for different reasons to those you are encountering. I rang RWC for advice and they were very helpful. Replacing the cartridge was very simple and it cured my problem. Initially I could not remove the cartridge from the valve body which made me suspect that there was some device holding the cartridge in place. Another Call to RWC and they adviced that I could use a screwdriver to prize out the cartridge to remove it.
Fitted new cartridge - Job Done

 

[mr-burns]

I see, thanks.

I presumed it would be fairly simple. So you just turn off the water, drain it a bit, and then unscrew the black plastic bit and screw the new one in? Are the pressure testing points just for diagnostics, or are you supposed to test it when it is installed?

Does anyone have any experience with the little pressure relief valves?

 

[Agile]

Whilst you will probably be able to change it yourself these unit should only be worked on by somebody with the required Certificate.

Tony

 

[mr-burns]

hmm, ok - so this is still subject to regulations then, even though it is the cold mains, not pressurised HW?

 

[Agile]

Hi,

Essentially my question is: "Can I replace the cartridges on pressure reducing and pressure relief valves?" Here is my reasoning as to what the problem is:

The cylinder is classed as an "appliance" and as such all aspects are covered by the regulations.

They can explode and bring down the whole house!

Tony

 

[mr-burns]

seems fair enough, but i'll be mightly hacked off if someone comes round and replaces the cartridges and doesn't then check the pressure!!!

Don't suppose anyone on here serves the Bow area? (in a plumbing sense) Would rather do that than play yellow pages roulette....

 

[mr-burns]

or anyone know if it is more likely to be the pressure reducing valve letting through static pressure, or the pressure relief valve just leaking?

 

[mr-burns]

So my girlfriend phoned a plumber, and they said that they think they'll have to replace the pressure reducing valve, at a cost of £160 (this is without seeing it)

I don't understand why they can't change the cartridge? (it's like £30 or less) I thought that was the whole point. Even replacing the whole valve, £160 seems like a rip off to me (valve can't be more than £50)

 

[Hysteresis]

As I said in my first reply mr-burns, I changed the cartridge myself in about 5 minutes at a cost of I think it was £25 for the cartridge. A little advice from RWC was welcome.
I think scaremongering of exploding water systems to be a bit over the top, but then again I am no plumber, but a cartridge replacement is hardly rocket science, and the device will limit the mains pressure. A faulty cartridge could allow mains pressure into the system which is far more damgerous that a simple cartridge replacement.
Give it a go and if that does not cure you problem then try the other approaches. Surley the only need to replace the whole valve assembly is if the valve body is damaged, if it isn't then a new cartridgre is the same as a new valve in my view.

 

[mr-burns]

sorry to bring this up again - I didn't want to do the work so as to stay on the side of the law (also, this is in an apartment block so there is a higher level of responsibility if it goes wrong)

So the plumber came round and said that they would change the pressure reducing valve, and would call when they could get the part.

They just rang, and said that it is a 'special' pressure reducing valve (which is just not true - rwc 312 series) and that it would cost £310 for the job.

This is just downright dishonest in my book - a replacement valve costs £50 max, and they are just taking advantage. This plumber was recommended to my girlfriend as they do a lot of the plumbing work in the apartment complex.

If I replace the cartridge, does it need adjusting for pressure??

I reiterate my previous request - is there an honest plumber on the forum who covers east london and like the business?

 

[Hysteresis]

The pressure reducing cartridge I bought from RWC was pre set to the pressure engraved on the cartridge - so, simple, take the old one out and put the new one in. Ring RWC and they are happy to give you all the advice you will need. As I said previously, replace the cartridge and see if it cures your problem, it is easy enough. If your problem is not cured, then turn to some reliable plumber.
If the guy who is suggesting £310 for the cartridge, why not ask him for a price to fit only any you buy the cartridge or complete valve directly yourself from RWC.(There may be very little difference in price between a cartridge and a complete valve, as the complicated bit is the cartridge assembly). I think he would be embarrassed what he would charge for 10 minutes work!!! Replacement is really that simple.

 

[OAPS]

Hi,

Essentially my question is: "Can I replace the cartridges on pressure reducing and pressure relief valves?" Here is my reasoning as to what the problem is:

My girlfriends flat in Bow, London. Megaflo direct HW system, and water is running through the tundish. I tried the 'replace air bubble' trick, which didn't stop it, so I tried to work out what it could be. The water in the cylinder is hot, but the water running through the tundish is cold, so it isn't related to the HW temp/press relief valve.

There is a drain pipe from the mains cold inlet control system which also runs to the tundish so I'm pretty sure that this is the problem.

Where the mains water comes in (just after the stopcock), it first goes through what appears to be (from picture search on their website) a Reliance RWC-SYR 312 series (312F I think) pressure reducing valve (it has 3 bar written on top of the black bit) and then into a RWC core manifold 8 bar pressure relief valve (looks like one of the two at the bottom of this page)

That same website has replacement cartridges for the reducing valve for £20/£30 (depending on size) and the relief valve for £7 - this would be a hell of a lot cheaper that getting a plumber round to sort it even if I don't identify which one is as fault and just do both.

I have done a fair bit of diy plumbing before, but am not sure as to how to replace these cartridges, or the regulations (I know there are some about pressurised HW systems). The little blue cartridge on the 8 bar relief valve has an anticlockwise arrow on it which I first thought about turning to see if it would maybe clear limescale or something, but now am glad I didn't as I can just see the cartridge pinging out and me getting covered in a LOT of water! The other small complication is that the pressure reducing valve is installed with the black catrtidge facing a wall, so I guess I would have to undo the nuts and rotate the whole thing 90deg to be able to remove the cartridge?

So, should I do this myself, or get a plumber?

Many thanks

Rob

It is now 2014, Time has moved on. My replacement cartridge purchased discount on line cost £100 ! I have tried to remove the old cartridge but it has disintegrated. It is looking as if I need a plumber, but it is Easter weekend ! I now intend to try to extricate the old cartridge with a screwdriver, as suggested elsewhere in this website. I am not optimistic but will report back if I succeed !

 

[picasso]

Where abouts in the country are you, plenty of us work over the bank holiday weekend.