Waste trap - cannot fix leak

[frank999]

I have a separate waste outlet for a washing machine (sink outlet goes to a Grease Trap, hence its separate), the trap has had recurrence of leaks several times over the last 18 months, i have had it all apart several times, last time replacing all the rubber seals.
The leak is not a huge amount of water, more like drips, but over months its causing some issues with the floor covers, and must be fixed.

The length of pipe where the flexi is inserted is reasonably long, but I guess one comment - is the flexible outlet from the washing machine could go into a 'hose connector' with a jubilee clip to seal it - at the top there, but other than that I'm at my wits end with it.

Have I done anything wrong.
I am considering replacing it all with solvent weld, creating a U bend with it - and adding an access plug, if ever needed, I can't think of anything bad that can come of doing that

 

[Old Salt]

You need a longer length of pipe for the drain hose to go into. Leaks could be splash back from that Tee fitting. The supporting brackets need to be holding the pipe rigid to prevent any misalignment. The smaller pipes need to be aligned to prevent any push or pull on the various joints. Get it all aligned without any strain and a couple of wraps of ptfe should sort out any minor drips.

 

[CBW]

Where is it leaking from?

 

[kidgreen61]

You have a leak because that is a bodge job, you need to install a spigot into the comp tee so that the flexi pipe fits properly

 

[frank999]

Thanks for your replies, all helpful.

Have I done anything wrong.
I didn't actually fit this - but hey ho ...

Agree the clipping should have been better to stop any strain on the joints, not sure why I didn't see that.

I did find a small leak at the top of the trap where the pipe is indented to allow a length of 40mm solvent pipe to fit over the top (here a short length goes up into the 'T'), glue had been used but the pipe simply pulled off - I suspect the plastic of the trap was not solvent compatible, in addition the orientation of this join, if failed (as in my case) allowed the waste water to pass through it to the outside of the pipe and drip down - why it was designed this way I've no idea, rubbish, it should have been 1) solvent pipe as the male (pipe from above) and 2) Trap pipe as the female (coming up from below). Not other way round as it was, a Toolstation distributed no name product.

Any way, Solvented the whole lot, no more leaks, I need to fill in around the hole in the wall, that will stop any vertical movement, and strain on joints. I could have added an access point - but its a silly length.
Am cautious about using a 'spigot', if the 40mm pipe gets blocked, the pumped waste water will push its way up through the Condensate Drain into the boiler, which is not what one wants, when you say Spigot, I assume you mean:

 

[Madrab]

Erm...I can kinda see why you did that, if you were at your wits end but the issue you may have now is that formed trap may gunge up and you have no way of cleaning it now without cutting it out, especially if it's a washing machine.

I think your original problem was a rubbish make of trap, you would have wanted to replace that with a proper McAlpine standpipe, with the condensate cut in lower down the vertical then one of these popped on the top.

As far as the water heading back up the condensate pipe, there really should be an air gap or similar - either a tundish/hottun/mcalpine tun5cl inline on the pipe so that doesn't happen. All too often there isn't one.

 

[frank999]

the issue you may have now is that formed trap may gunge up and you have no way of cleaning it now without cutting it out,
Yep I agree, but unless anyone using the washing machine is going to be a butcher or abatoir employee (ie grease) I can't see that getting blocked, I have 20 year old pipe doing the same job without any blockages.

I think your original problem was a rubbish make of trap
Yes agree, just for the sake of a few £, McAlpine it should have been.

there really should be an air gap or similar
I'm trying to process the setup in my head, any images of what you suggest ?

 

[Old Salt]

I still think its worth adding a small length of pipe to the tee where the drain hose goes in. Suitably bracketed of course and it would need a waste pipe compression fitting to fasten to the tee.
Otherwise, good job but don't take that job in the abattoir

 

[frank999]

I still think its worth adding a small length of pipe to the tee where the drain hose goes in
Is that to make the overall pipe length longer, the flexi pipe reaches down inside to below where the T joins ...

 

[Old Salt]

I still think its worth adding a small length of pipe to the tee where the drain hose goes in
Is that to make the overall pipe length longer, the flexi pipe reaches down inside to below where the T joins ...

To make the drain hose enter higher and prevent drain back

 

[Madrab]

I'm trying to process the setup in my head, any images of what you suggest

I assume there is a vertical leg in the condensate run, if so then you would cut one of these, or similar into the run

It provides a visible air gap for fault identification but also incorporates a non return valve to avoid smells, other standard open air (dry) tundishes can also be used.

 

[Alec_t]

Solvented the whole lot, no more leaks

But how do you propose to clean the now non-removable U-bend when it inevitably gets clogged up?

 

[frank999]

But how do you propose to clean the now non-removable U-bend when it inevitably gets clogged up?
I refer you to the abattoir comment previously

It provides a visible air gap for fault identification but also incorporates a non return valve to avoid smells
Thats a good suggestion, but would the u'bend I have created not deal with any smells that might be the other side, this side of the 'u' has minimal run lengths of pipe, and is not connected to anything that would produce any rank smells.

 

[Madrab]

but would the u'bend I have created not deal with any smells that might be the other side

Yes, but it isn't visible (for the condensate) nor serviceable, which any well designed waste run and certainly a condensate run should be.

 

[frank999]

but it isn't visible (for the condensate) nor serviceable
Thanks, all good points, and agree, see a need for the visible air gap..
I'm not working in an abbatoir, fortunately.

I can't find the clear version though, only this:

In-Line Vertical Non-Return Valve | McAlpine Plumbing

Optimize your plumbing system with the In line Vertical Non Return Valve, ensuring efficient water flow and preventing backflow.

mcalpineplumbing.com

This document is helpful:

Heating and Hot Water Industry Council: Condensing Boiler - Industry guidance for installers
Is a 'visible' check point fitted just to check for freezing of the Condensate Pipework.
In my circumstances that shouldn't be an issue, the run is internal in a heated room, if condensate wasn't flowing down the pipework due to a blockage, you would most lilely already be aware of that due to something else, but this run of 40mm pipe work is dedicated to just the washing machines, sinks go down on another run, with a grease trap on the end, so unless abbatoir overalls are being washed without detergent, I cannot see it needing to be servicable.

The guidance states;
Manufacturer’s instructions must be followed ... a visible air break and trap is not required if there is a
trap with a minimum condensate seal of 75 mm incorporated into the boiler.

I have a Vaillant Eco Tec Combi, which has a trap I believe.

As an aside, where the Condensate drains to a soak away - you need to have an additional 'filter' to remove 'acid' from the condensate, think it has lime chippings in to neutralise it, wouldn't want acid leaching into the ground, and poisoning everything around.
How much of this Acid must be in our water system !