Still having problems with condensate pump

Britannia12345

I posted a few weeks ago about my dodgy condensate pump and I'm still battling with it.

Our boiler is in an interior pantry and the pump sends the water up to the attic and outside. The pump keeps getting stuck on and it's baffling me. Sometimes it empties just fine, then other times it just keeps running until the whole thing overheats and knocks the heating off.

The only way I can get it to work again is to take the plastic pipe that goes into the attic off the pump and let the built up water out of it into a bowl, then reattach the pipe and it works fine for another day or so then decides to jam again.

I've checked the pipe in the attic and all seems well. I've tested for blockages by pouring water down it and that's all fine and the pipe leading out the attic seems ok too.

Any tips or tricks I can try before getting a plumber out? If I don't get it sorted soon I'm scared it's going to burn the pump motor out 🤔

WIAWSNB

How old is it?

I have to say, the most obvious culprit is simply a sticking float switch.

How DIYable are you? Sounds like a great project ☺️

Make and model and pic?

How dismantleable is it?

Britannia12345

Not sure how old it is as it was in the house when we bought it.

I'm baffled as to why it's not pumping the water up to the loft when it's stuck on. Surely the pipe should be empty as long as the pump is running?

My son is good at tinkering with things so he might be able to have a poke at it.

The model is a Grundfos (I think - it's hard to read)

The cover lifts off so you can get to all the gubbins inside.

WIAWSNB

Thanks, I'll look it up. Conlift 1-LS?

Sorry. I misunderstood - I'd assumed the issue was that it would just not stop pumping, but actually it is that it runs but doesn't pump effectively?

Can you see where the condensate collects from the boiler? It definitely has enough liquid in there? Ie, it ain't trying to pump dry - pushes the liquid that is there up t'pipe, and then spins dry?

Can you see the outlet outside? I guess one obvious thing to try is to connect a hose to the pump end, and check that it flows out without issue, but almost certainly that's fine.

You say the pump overheats? And that trips the boiler? What fault reading does the boiler give - a condensate problem?

https://share.google/w4ypC4Mm7cxTpNE1l

Britannia12345

Yep that's the one. The tank under the pump fills up but the pump doesn't send it up the pipe. If the pipe isn't on the pump it shoots water out of the nozzle but my son wondered if it's not strong enough to pump it high enough. That doesn't make sense though as it works part of the time.

If it runs too long with the pipe full of water it overheats and knocks the boiler off completely, no error codes or display.

I'm stumped 🤔🥴

WIAWSNB

I'm stumped too. Especially how it knocks out the boiler without giving an error code (boiler make and model?)

What do you mean by 'knocks out'? Does it trip the MCB?

It is quite possible, of course, that it's behaviour is intermittent, just like the drain pump on my washing machine. After the failure to pump increased, I took the bar steward out and cleaned away all the hairs caught around t'spindle. Worked perfectly. Until 2 days ago… Grrrr. And working fine since.

I'm assuming it's the pump at fault, but I guess it could be the electronics governing it.

Britannia12345

It's a Baxi 800. It just turns the whole boiler off. I let the pump cool down, drain the pipe, switch it all back on again and all is fine for a while.

Your washing machine pump sounds just as infuriating 😭🤣

WIAWSNB

I still don't know what you mean by turning the boiler off. Does it lose all power? Go 'dead'. No lights, now't?

It has a wee display that shows error codes, yes?

bjorn_toby_wilde

https://forums.moneysavingexpert.com/discussion/comment/81894405#Comment_81894405

The Conlift has a built in sensor which is either wired to an alarm or the condensate source (boiler in this case). When it can’t empty its tank the sensor will either a) sound an alarm or b) turn off the boiler. Sounds like this one is wired to turn off the boiler.

The Conlift can pump up to about 5.5 metres high so OP you need to check whether it’s being asked to pump higher than it is capable of pumping or (more likely) the pipe has become fully or partially blocked. If it’s definitely neither of those then maybe the pump has had it. I’ve had one of these for 20 years without issues but it only has to pump about 2.5m high so it’s not working as hard.

Britannia12345

Yeah, the boiler turns off completely, no display.

I'm trying to work out how high it's pumping. We live in a bungalow.

bjorn_toby_wilde

https://forums.moneysavingexpert.com/discussion/comment/81894452#Comment_81894452

probably not 5.5m then. A bungalow should be well within its capabilities.

When you say “pumps up to the attic then outside” how exactly is it routed? If the pipe shown in your photo is outside at any point there’s a good chance it could freeze up. It looks like the pipe on mine; quite narrow (about 10mm internal diameter).

Mine is insulated and runs into an internal 4”plastic soil pipe. Any pipe runs that might freeze need to be at least 32mm. 40mm ideally.

Given what you’re describing with the pump squirting out water as soon as you disconnect the pipe, I’d put money on a blockage somewhere in the pipe run.