MVHR help water in pipes!

[hotnuts21]

A friend of mine has a newish house (10yrs ish old) and it's has a cheap MVHR unit in the loft. 

 

It's been ok, although its leaked a few times.  About a month ago she was told a leak she'd noticed on the bedroom ceiling was coming from the small 'waste/condensate? pipe at the bottom which had been bodged with so much mastic the replacement parts weren't available and what they (local heating company) could get didn't and wouldn't fit. 

 

So she was advised to switch it off. 

 

She went into the loft this week and the small white pipe which goes up to a roof vent is full of water and dropping in places. 

 

I'm gonna go and hopefully help her drain them, whilst waiting for the quote for a new unit. Any tips on how greatfully received 

 

However, what I can't understand is where is the water coming from in the pipes? Why is so much building up with the unit off? 

 

I'm still looking to install my own unit, so all possibilities are a good learning experience too. 

 

Some photos below and wow my first though was mega bodge and amazed it lasted 10yrs. 

[Eric]

An absolute bodge as you have said.

Water is probably condensation in the hoses. That type of hose shouldn’t be used, should be plastic pipe installed with flexible connections on the unit & silencers etc.

 

I have installed a Vent Axia unit previously & was very pleased with it as with others on here.

Probably best to disconnect all hoses & stop the water/condensation first.

 

Edit. Unit in a cold attic needs to be well insulated along with the ducts.

Edited January 10 by Eric
Added info.

[hotnuts21]

This is/was the waste/condensate pipe that's been leaking and started the problems. Installed like this 🤮

[Conor]

Complete shitshow. Tbh probably need a company in that knows what they are doing to redo the ducting and condensate pipework. Either that or spend a few a few hours here reading through the many posts and have a go yourself / help your friend out. Probably nothing wrong with the unit, it just looks like it was installed on a Friday afternoon by an unsupervised apprentice.

[Russdl]

The white pipe filling with water looks like a tumble dryer hose!
 

I presume it’s ‘exhaust’. I can’t quite work out the orientation of it, Is it just filling up with rain?

 

What does the outside look like?

[markc]

Condensate drain running up hill? No wonder it’s filling with water

[Marvin]

Oh dear!

 

We have an HRX2 with no problems.

 

However only after installing did we understand that all ducting and the MVHR unit needs to be inside the building thermal envelope to obtain proper benefits regarding saving heat in winter and cooling in summer!!!

 

This is the "one way" waste connector we have fitted...

 

https://www.i-sells.co.uk/domus-green-line-mechanical-ventilation-with-heat-recovery-condensate-drainage-kit-white?gclid=Cj0KCQiAwP6sBhDAARIsAPfK_wYvtNFQ06YTJNrp2FcwUG_o-N1L47Mj2wMqy8FUC0WHoCT-YlkamPMaAiSbEALw_wcB

 

Our condensate waste pipe is down hill all the way!

 

We have rigid ducting all insulated.  We usually clean the filters every 6 months.  Also think the bottom of the MVHR unit needs to be level.

 

You really do not want to turn the unit off: Moist air entering the exhaust pipes from shower rooms etc will condense in the pipes rather than in the unit causing more problems!!!

 

 

Marvin

[Blooda]

13 minutes ago, Marvin said:

 

https://www.i-sells.co.uk/domus-green-line-mechanical-ventilation-with-heat-recovery-condensate-drainage-kit-white?gclid=Cj0KCQiAwP6sBhDAARIsAPfK_wYvtNFQ06YTJNrp2FcwUG_o-N1L47Mj2wMqy8FUC0WHoCT-YlkamPMaAiSbEALw_wcB

 

 

 

This what I Used:-

 

Viva Magna Self-Sealing Waste Valve 32mm | Toolstation

 

There looks like one similar in the blue highlight, but as the drain is going up hill then there's no hope of it draining

 

@hotnuts21 She needs to get someone in to sort out the ducting and the unit will hopefully ok.  Need to look for a local Refrigeration or HVAC engineer who should be able to sort it out.

 

At the moment it has the potential to cause more harm than good.

 

I bet the filters have not been cleaned / replaced, causing efficiency issues.

 

 

Unrelated, but idea what this pipe is ?

 

 

[hotnuts21]

HI all,

thanks for the great responses, I've summarised the main points and responses below and added some more information.
The builder was a bodger, I think he threw all new tech at the house without knowing what it was.  The ASHP for example has had a load of issues and didn't have a magnetic filter on the system and was constantly running at full whack until someone from Daiken sorted it. So this is another chuck it in and see I think, although its been working pretty well for 8-10 years. Apparently up until about 18 months ago it was rattling because the fan speed was constantly on max, an electrician turned it down and she thinks that when the leak might have started took a while to notice the damp patch in the corner. 

1, the orientation of pipes, etc!

 - I think this is a trick of the camera and the angles she took the photos in with the loft etc, the drain seems to run parallel to the floor/roof joists so I'm pretty sure it's running straight, but I'm hoping to get in there and have a look this weekend.

 

2, Cause

 - So it seems we think the water building up is just warm air coming up through the ducts, into the pipes, and condensing because the units not on.

3, Clear the water from the pipe(no idea how but I'll give it a go, just disconnect from the machine and manipulate it through the pipe to a bucket) and put the unit back on for now, but put a bucket under the faulty drain to collect the leak that started all this. I will also open the machine and see whats going on inside if the condensate is blocked etc.

4, Look at fitting/fixing the drain as in the interim.

 

5, Look at getting someone in to redo the pipework at least in the loft who knows what they are doing.  The local heating and engineers company that has looked at it and drained the hoses before Christmas just said it needed replacing and couldn't be fixed, but I've asked her to get a written reason why so I can see if they even realized the pipes were wrong, maybe they were talking about the pipes, etc only.  But im not convinced anyone locally fully understands MVHR with conversations I have had recently with plumbers and sparks. Ill keep looking though.

 

6, She has changed the filters several times.

The silver pipes are the correct type? Is it just the outgoing white pipe (I hope it's the outgoing) that needs better lagging and placement?

Oh, and the grey pipe is I think the Soil pipe, but no idea why it's running flush with the roof angle. She told me she has 3 vents on the roof so I'm guessing two for MVHR and one for the soil pipe. But I'll try and get some more pics.

 

Edited January 11 by hotnuts21

[hotnuts21]

I also have to say I'm quite impressed that the black tape holding the inlet up and to the rafters has lasted that long 😄  But having another look at the condensate pipe run, im wondering why it seems to be going in the opposite direction to the soil vent and rather right to the eaves...

[Blooda]

 

Simple but effective Check List from the Vent Axia Installation Manual

More to it than that, such as the ducting should be rigid with a small section of flexi and that trap shows a wet trap. 

Flexi creates more turbulence which will affect performance / electric efficiency and more noise, also more likely to cause duct build up.  Also more prone to damage.