Bilge pump in the cellar, only partly non boaty

[DoubleEnder]

I have a damp cellar, really quite damp. If I run a dehumidifier it is useable, and the dehumidifier doesn't use a lot of juice. But then you have to empty the tank, regularly. Pain. So I am thinking I'll put a cheap 12v combined bilge pump/float switch in the tank, and let the thing pump itself away.
Question: what sort of 12v transformer do I need? It will be plugged in and left switched on, long term. I will fuse it and also put a fuse inline for the pump. But most 12v transformers in the world according to Google seem to be designed to run LEDs. I assume they are not man enough...? I think a small bilge pump will draw about 3amps when pumping.

Also, of course, is this a stupid/dangerous idea? Are there better plans? I cant afford to tank the cellar.

Thank you
Graham

 

[simonfraser]

Use an AC water pump, they have small automatic pumps for the condensation, mains too

 

[lw395]

A float switch and windscreen washer motor pump might work better.
Most of the cheap bilge pumps only lift water about 6ft, so unless which put the dehumidifier high up, may not work.
There are plenty of fairly cheap 12V supplies which will do 3A or more, often sold as generic adjustable laptop supplies.

 

[nimbusgb]

You need a 12 v dc power supply not a transformer. Maplin do a reasonable one capable of 5 amps or so.

How far do you have to pump the water? What is the 'head'. ( if its from a basement floor then probably 2m or so) You may not be able to pump the water high enough to drain it properly. Otherwise you will have to run the hose up higher than the drain point quickly with a good run to the drain to ensure that when the pump stops the water downstream of the loop syphons enough out of the rise to prevent it backfilling the reservoir. It may be easier to mount the dehumidifier above the basement with the air in and out ducted to it!

 

[DJE]

Why not use mains power:-

https://www.machinemart.co.uk/shop/product/details/hippo-2a-1in-water-pump-with-float-swi

Long term rather than tanking I would use an internal drained cavity system like this:-

http://www.maclennanuk.com/index.php/cavity-drain-system

 

[DoubleEnder]

Yes maybe a mains pump would be better, thank you. The cellar isnt flooded, just really damp. I thought if I mount the dehumidifier up on a shelf, the pump will only have to lift the water a short distance, less than 1 metre

 

[lw395]

Yes maybe a mains pump would be better, thank you. The cellar isnt flooded, just really damp. I thought if I mount the dehumidifier up on a shelf, the pump will only have to lift the water a short distance, less than 1 metre

Should be fine then. You need to make sure the pump does not keep cycling due to the water running back when the pump stops, re-triggering the float switch.

 

[pete]

We fitted condensing pumps under condensing boilers when there was no downward rout to a drain, the kits include a catchment chamber with a float switch built in also come with a length of flexible plastic pipe and are 240v.
Like these https://www.youtube.com/watch?v=k0YdUahUXjc

pete

 

[ghostlymoron]

My cellar is REALLY damp with water ingress after heavy rain presumably because of the water table being raised. After two years of trying to plug the leak points with Wataplug, I fitted a 240v pump with float switch. Its still damp but no standing water.

 

[Daydream believer]

A lot depends on the ground conditions outside the cellar ( particularly the level of the water table or the source of water) but one way to improve the cellar would be to drill 19mm holes through the wall at 2ft centres all around the walls at about 6-9 inches up
Insert 19mm plastic pipes in each & connect to "T" pieces with a pipe around the wall connecting them all up. lead this pipe to a sump. Ordinary Osma overflow pipe is OK & is cheap
Then fit a sump pump. Of course you will need to form a sump first
This reduces the water pressure outside the basement. At first you might get lots of water coming in but depending on the soil it will stop after a while & only run water in very wet conditions
Assuming that a couple of walls of the basement are on the line of the main house external wall It also helps to have a non porus surface outside at ground level so that water does not drain down the side of the house straight down any walls of the basement
By removing some of the water pressure outside it has a tendancy to reduce the dampness. If after a year ( it will not seem to work for a couple of months) it does not help it is no big deal to block the holes up & go back to square one. If the pipes do drain water when it rains or in damp weather conditions then you have a source of water & can act accordingly. If nothing at all happens then a simple render to the walls will be ok ( but leave the pipes in)

I would tend not to use a dehumidifier as it just drags more moisture through the walls

If you reduce the water pressure & there is a drop in moisture content then you can render the inner walls at some point in the future with waterproof render ( £ 45-00-£55-00 per M2 should cover it)
That can be done by a local plasterer rather than pay someone, like Sika, exhorbitant prices
You can still buy sika products for the actual render

 

[DoubleEnder]

I love the forum. Some great ideas here, thank you very much everyone