Replacing toilet flush

[The Gauge]

My second toilet flush thread this week....but this is a different toilet.

Whilst I'm in DIY plumbing mode I want to replace this toilet flush which from researching is I believe a SIAMP brand which are known to be poor...




I have ordered a Fluidmaster PRO45B to replace it, however I can't access the plastic nut that secures the SIAMP unit to the underneath of the cistern, it's concealed as the toilet goes right back to the wall...




So is it as simple as turning off the water supply, flushing/draining the cistern, and unscrewing the two rusty screws that secure the cistern to the wall, lifting it off and then accessing the plastic nut? Then reassemble in reverse?

Edited by The Gauge on Monday 30th December 12:19

[74merc]

I've replaced two of these recently and from memory,you are spot on. I would also replace the close coupled seal as well, since on both occasions, I couldn't get it to seal properly afterwards.

[GasEngineer]

There's usually a couple of fixings holding the cistern to the pan as well.

You may have to unscrew the floor fixings and pull the whole thing forward.

[The Gauge]

GasEngineer said:

There's usually a couple of fixings holding the cistern to the pan as well.

You may have to unscrew the floor fixings and pull the whole thing forward.

Mmm, that would also probably mean disconnecting the waste pipe at the back I assume? Might be a job I prefer my plumber to do, though I don't think he likes doing toilet jobs these days and sticks to just heating work.

For now I might just replace the rubber diaphragm in the unit, however I cant undo the cap, it's on too tight to loosen by hand, Mole grips and pliers can't get a purchase either as they slip off in the restricted space available. Can anyone think of a tool that would help?

Edited by The Gauge on Monday 30th December 14:35

[GasEngineer]

I use a pair of grips like this:

https://www.amazon.co.uk/Bahco-2971G250-Joint-Plie...

[alabbasi]

I can't offer advice other than to say that UK toilets are such a pain in the rear to work on. This looks like a gravity filled tank valve vs the ballcock style. Maybe look at some online to see if you can find instructions. I hope that they all work the same way but the last time I went to a plumbing supply store in the UK, they told me that 'they were all different'.

[JimM169]

The Gauge said:

Mmm, that would also probably mean disconnecting the waste pipe at the back I assume? Might be a job I prefer my plumber to do, though I don't think he likes doing toilet jobs these days and sticks to just heating work.

For now I might just replace the rubber diaphragm in the unit, however I cant undo the cap, it's on too tight to loosen by hand, Mole grips and pliers can't get a purchase either as they slip off in the restricted space available. Can anyone think of a tool that would help?

Edited by The Gauge on Monday 30th December 14:35

Waste will just be a push fit and I'd suspect that as it's a back to the wall design it will be on a flexible waste so may not need to disconnect anyway.

[borcy]

The Gauge said:

Mmm, that would also probably mean disconnecting the waste pipe at the back I assume? Might be a job I prefer my plumber to do, though I don't think he likes doing toilet jobs these days and sticks to just heating work.

For now I might just replace the rubber diaphragm in the unit, however I cant undo the cap, it's on too tight to loosen by hand, Mole grips and pliers can't get a purchase either as they slip off in the restricted space available. Can anyone think of a tool that would help?

Edited by The Gauge on Monday 30th December 14:35

Oil filter removal tool, one of the thin belt ones?

[miroku1]

Those siamp flush valves aren’t the best , but it takes about 20 seconds to change like for like , which is a lot easier than stripping the whole lot out and replacing with an alternative which won’t be much of an improvement.

[The Gauge]

borcy said:

Oil filter removal tool, one of the thin belt ones?

Good idea, whilst I'd like to own a nice pair of slip joint pliers I've instead ordered a thin belt oil filter removing tool from Amazon for £6 delivered tomorrow, fingers crossed.

[borcy]

The Gauge said:

borcy said:

Oil filter removal tool, one of the thin belt ones?

Good idea, whilst I'd like to own a nice pair of slip joint pliers I've instead ordered a thin belt oil filter removing tool from Amazon for £6 delivered tomorrow, fingers crossed.

I had the same problem with the same brand inlet valve, i used a set of mole grips but had disconnect some stuff first. Those wheels on the inlet valve are surprisingly stiff!

[The Gauge]

Spent my New Years Eve afternoon repairing the toilet flush. The oil filter tool did the trick

Decided not to bother trying to pull the toilet away from the wall to replace the fill valve, instead ordered a new rubber diaphragm. Removed the old diaphragm which had perished completely (on the right)




New diaphragm inserted..




I'll let the plumber replace it all with the new Fluidmaster kit I bought when he next visits. Cistern now takes 55secs to refill compared to the 10mins it was taking. Looking forward to a flushtastic 2025

Edited by The Gauge on Tuesday 31st December 16:18

[droopsnoot]

What was the actual fault, out of interest? I've got a SIAMP flush valve and it's always running a very small trickle, leading to it having to periodically fill itself up, so it's wasting water. I've seen a few YT videos that show the bottom rubber seal can get "stuff" on it, and cleaning it off might sort it. I don't fancy having to take the cistern off, apparently you can undo them by turning the mechanism, but I keep finding excuses not to do it, in case it all goes wrong. Excuse to not do it tomorrow is in case I break it and can't get another.

[tux850]

droopsnoot said:

I've got a SIAMP flush valve and it's always running a very small trickle, leading to it having to periodically fill itself up, so it's wasting water. I've seen a few YT videos that show the bottom rubber seal can get "stuff" on it, and cleaning it off might sort it. I don't fancy having to take the cistern off, apparently you can undo them by turning the mechanism, but I keep finding excuses not to do it, in case it all goes wrong. Excuse to not do it tomorrow is in case I break it and can't get another.

Yeah, cleaning the seal is usually all that needs doing on the flush valves. Scale and other crud can prevent improper sealing. It sounds like you've seen this being done so I'll spare the detailed instructions, but suffice to say the internal mechanism is easy to remove - it just twists (anti-clockwise) allowing you to remove the whole thing and access the seal beneath. You don't even need to turn the water off as the running water from the inlet valve will just run straight down into the pan. You can wedge the float valve at the top though to prevent this is required.

[borcy]

Where did you get the replacement seal from?

[droopsnoot]

tux850 said:

Yeah, cleaning the seal is usually all that needs doing on the flush valves. Scale and other crud can prevent improper sealing. It sounds like you've seen this being done so I'll spare the detailed instructions, but suffice to say the internal mechanism is easy to remove - it just twists (anti-clockwise) allowing you to remove the whole thing and access the seal beneath. You don't even need to turn the water off as the running water from the inlet valve will just run straight down into the pan. You can wedge the float valve at the top though to prevent this is required.

Thanks, I did see a video on it. I had a go at removing the thing by twisting it but I couldn't get it to go, though another video (from SIAMP) says I should push down and twist. I've been putting off having another go at it, but I must get it done soon.

[Mr Pointy]

borcy said:

Where did you get the replacement seal from?

. https://shop.siamp.co.uk/valve-spares
https://www.toiletspares.co.uk/siamp.html
https://www.amazon.co.uk/s?k=SIAMP+SEAL+DIAPH&...

[The Gauge]

Mr Pointy said:

. https://shop.siamp.co.uk/valve-spares
https://www.toiletspares.co.uk/siamp.html
https://www.amazon.co.uk/s?k=SIAMP+SEAL+DIAPH&...

Amazon

[borcy]

Mr Pointy said:

borcy said:

Where did you get the replacement seal from?

. https://shop.siamp.co.uk/valve-spares
https://www.toiletspares.co.uk/siamp.html
https://www.amazon.co.uk/s?k=SIAMP+SEAL+DIAPH&...

Thanks