New dishwasher not draining - hose angle?
Discussion
Hi all
Just wondered if anyone has experienced this or if I am being fobbed off
New integrated dishwasher to replace 6 year old one that gave up.
Its not draining so called manufacturer who advised the drain hose has to go immediately up to 40-80cm, then along for however long before dropping down towards the drain point. Said that running along the floor then up to the drain pipe is too much for the pump.
Tested it while it was out and it worked at a higher height than that but when you put it back in place there is no room for the hose so it has to go sideways approx 20cm first. Which I assumed is why integrated dishwashers are shaped how they are with that “cut out” at the bottom to go sideways.
So pump has strength to go higher than recommended when the hose is pointing immediately up as it leaves the dishwasher but if you have even a slight horizontal first then it fails.
Instructions say hose should go along the floor then up. And previous dishwasher worked fine like that.
Should it really be that sensitive to a little directional difference or am I right to suspect they know there is an issue with a batch of their units and are trying to fob me off with a work around
Just wondered if anyone has experienced this or if I am being fobbed off
New integrated dishwasher to replace 6 year old one that gave up.
Its not draining so called manufacturer who advised the drain hose has to go immediately up to 40-80cm, then along for however long before dropping down towards the drain point. Said that running along the floor then up to the drain pipe is too much for the pump.
Tested it while it was out and it worked at a higher height than that but when you put it back in place there is no room for the hose so it has to go sideways approx 20cm first. Which I assumed is why integrated dishwashers are shaped how they are with that “cut out” at the bottom to go sideways.
So pump has strength to go higher than recommended when the hose is pointing immediately up as it leaves the dishwasher but if you have even a slight horizontal first then it fails.
Instructions say hose should go along the floor then up. And previous dishwasher worked fine like that.
Should it really be that sensitive to a little directional difference or am I right to suspect they know there is an issue with a batch of their units and are trying to fob me off with a work around
What make is it?
We've got an integrated Neff - so same as Bosch and Siemens - and the hose goes along the floor then the very end of it come up to sink cabinet to the sink u-bend and joins a spigot there, with the spigot pointing downwards, so the drain hose never gets to any height. This is how the kitchen fitters installed it and it works fine.
I did have some other problem with the machine and ran it while pulled out, with the drain going into a bucket, and flow rate and power out of the drain hose surprised me, it's like a fire hose for the few seconds it takes to drain.
We've got an integrated Neff - so same as Bosch and Siemens - and the hose goes along the floor then the very end of it come up to sink cabinet to the sink u-bend and joins a spigot there, with the spigot pointing downwards, so the drain hose never gets to any height. This is how the kitchen fitters installed it and it works fine.
I did have some other problem with the machine and ran it while pulled out, with the drain going into a bucket, and flow rate and power out of the drain hose surprised me, it's like a fire hose for the few seconds it takes to drain.
Hotpoint. Old on was a Kenwood.
Same setup as above. Dishwasher space immediately next to the cupboard with the sink waste so majority of the hose sits on the floor and just rises up for the spigot.
I have made sure its all flat on floor flat with no kinks.
Only difference is I changed the spigot for more tapered one as I struggled to get the hose to connect and the new spigot is horizontal not angled. Not sure that would be a factor as its only a couple inches long and the internal of the part where it meets the sink waste has a downward pointing interior if that makes sense - to stop water back flow from the sink. So effectively a very small horizontal section.
Incidentally when I tested into a bucket it was more like a tap pressure. Not slow but certainly not fast.
Same setup as above. Dishwasher space immediately next to the cupboard with the sink waste so majority of the hose sits on the floor and just rises up for the spigot.
I have made sure its all flat on floor flat with no kinks.
Only difference is I changed the spigot for more tapered one as I struggled to get the hose to connect and the new spigot is horizontal not angled. Not sure that would be a factor as its only a couple inches long and the internal of the part where it meets the sink waste has a downward pointing interior if that makes sense - to stop water back flow from the sink. So effectively a very small horizontal section.
Incidentally when I tested into a bucket it was more like a tap pressure. Not slow but certainly not fast.
Pretty sure this is a physics thing - your horizontal run of pipe has air in it which the pump can't push. Air usually goes up or down through water but a horizontal pipe collects air.
Even having a constantly rising diagonal pipe would solve that one.
It isn't a problem of dishwashers themselves, probably all of them have similar pumps like this that can only push water.
Extra note - like even if 10% of your horizontal pipe is air, the pump will probably fail to push the water through.
Even having a constantly rising diagonal pipe would solve that one.
It isn't a problem of dishwashers themselves, probably all of them have similar pumps like this that can only push water.
Extra note - like even if 10% of your horizontal pipe is air, the pump will probably fail to push the water through.
Edited by Jaska on Saturday 29th November 22:25
menousername said:
Hotpoint. Old on was a Kenwood.
Same setup as above. Dishwasher space immediately next to the cupboard with the sink waste so majority of the hose sits on the floor and just rises up for the spigot.
I have made sure its all flat on floor flat with no kinks.
Only difference is I changed the spigot for more tapered one as I struggled to get the hose to connect and the new spigot is horizontal not angled. Not sure that would be a factor as its only a couple inches long and the internal of the part where it meets the sink waste has a downward pointing interior if that makes sense - to stop water back flow from the sink. So effectively a very small horizontal section.
Incidentally when I tested into a bucket it was more like a tap pressure. Not slow but certainly not fast.
You’re sure you removed the blanking piece from the spigot?Same setup as above. Dishwasher space immediately next to the cupboard with the sink waste so majority of the hose sits on the floor and just rises up for the spigot.
I have made sure its all flat on floor flat with no kinks.
Only difference is I changed the spigot for more tapered one as I struggled to get the hose to connect and the new spigot is horizontal not angled. Not sure that would be a factor as its only a couple inches long and the internal of the part where it meets the sink waste has a downward pointing interior if that makes sense - to stop water back flow from the sink. So effectively a very small horizontal section.
Incidentally when I tested into a bucket it was more like a tap pressure. Not slow but certainly not fast.
miniman said:
You re sure you removed the blanking piece from the spigot?
And that the end of the spigot isn't too narrow?If the instructions say to install with the hose horizontal then I'd expect it to work. As in the OP, you wouldn't normally get the drain going immediately upwards from an integrated dishwasher.
Edited by Sheepshanks on Saturday 29th November 22:31
Sounds like there’s something wrong with it.
I’d bet 90% of the dishwashers in the land just have the drain hose haphazardly routed from the base of the back of the machine to think sink unit next to it where it connects to a spigot on the waste.
As long as the pump isn’t cavitating any air in the pipe will be displaced.
Our new Bosch lasted about two weeks before it refused to empty and was due to an internal leak.
I’d bet 90% of the dishwashers in the land just have the drain hose haphazardly routed from the base of the back of the machine to think sink unit next to it where it connects to a spigot on the waste.
As long as the pump isn’t cavitating any air in the pipe will be displaced.
Our new Bosch lasted about two weeks before it refused to empty and was due to an internal leak.
Crumpet said:
Sounds like there s something wrong with it.
I d bet 90% of the dishwashers in the land just have the drain hose haphazardly routed from the base of the back of the machine to think sink unit next to it where it connects to a spigot on the waste.
As long as the pump isn t cavitating any air in the pipe will be displaced.
Our new Bosch lasted about two weeks before it refused to empty and was due to an internal leak.
Yup. Not a chance in hell that a single manufacturer designs a system that would require a plumber to follow some basic but essential instruction for the pipe. I d bet 90% of the dishwashers in the land just have the drain hose haphazardly routed from the base of the back of the machine to think sink unit next to it where it connects to a spigot on the waste.
As long as the pump isn t cavitating any air in the pipe will be displaced.
Our new Bosch lasted about two weeks before it refused to empty and was due to an internal leak.
Besides, the potential energy used/required would be the same however the pipe was slung about round the back. It's still just got to go from A to B.
I'd be tempted to ask the company employee to explain the fluid dynamics and physics of what it is that they're saying as well as asking why the pipe exit isn't at the top of the machine rather than the bottom if the external pipe then needs to randomly be raised to the top point. Or one could save time and just shout bulls
t down the phone followed by the instruction to come and remove. Jaska said:
Pretty sure this is a physics thing - your horizontal run of pipe has air in it which the pump can't push. Air usually goes up or down through water but a horizontal pipe collects air.
Even having a constantly rising diagonal pipe would solve that one.
It isn't a problem of dishwashers themselves, probably all of them have similar pumps like this that can only push water.
Extra note - like even if 10% of your horizontal pipe is air, the pump will probably fail to push the water through.
The pump is in the machine and pushing water out. It's not trying to suck it in, which would need a self-priming pump.Even having a constantly rising diagonal pipe would solve that one.
It isn't a problem of dishwashers themselves, probably all of them have similar pumps like this that can only push water.
Extra note - like even if 10% of your horizontal pipe is air, the pump will probably fail to push the water through.
took me ages to figure out the obvious!Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff