Can I clear a dishwasher blockage with caustic soda?

[peter964rs]

Tenants have phoned and say the dishwasher is not draining. They have cleaned the filter and also run a cycle with a cleaning product for dishwashers, which also seemed to help slightly, however it is still not draining. They have felt through the drain hole past the filter slightly and can't feel any blockage, but plainly it isn't draining.

Am I OK to recommend some caustic soda followed by boiling water later, or just boiling water? Not sure if caustic soda is a bad idea for a dishwasher...

 

[TicklyT]

This may be better asked in the appliance section.
In my limited experience of dishwashers, there may be a problem with the pump or valve controlling the drain.

If you do load it up with caustic soda, and it doesn't work, what will you do with a dishwasher full of corrosive liquid?

 

[zipper]

Caustic soda .....not a good idea.
Posting the make & model might be.

 

[peter964rs]

It's a Baumatic BDI631

Very good point about having a dishwasher full of nasty stuff. Any ideas welcome - tenancy arrangements being what they are, I am responsible if something needs replacing or repair through normal wear and tear, whereas my tenants are responsible for maintenance and I am entitled to charge them if I (for example) come out to unblock a sink for them.

I don't want to charge them but equally they've called me out for maintenance type work before (e.g. rehanging a blind, adjusting a cupboard door) and I want to politely draw the line

Not sure what to recommend other than checking all the filters once more and pouring some kind of sink/drain de-blocker down there

 

[Diyisfun]

I would have a guessed at the pump being faulty/blocked.
The crap I put in my dishwasher, I dont use a hot wash, never any problems.

 

[captaincaveman1]

If its connected to a sink spigot (a nozzle on the sink u bend) it could be worth removing that and checking it isnt blocked with fat

 

[ohmagain]

Unfortunately solutions like caustic soda, hydrochloric and sulphuric acid drain cleaning and unblocking solutions are designed for breaking fat and solids in plastic (or old clay/lead) pipework, But these also have a appetite for rubber, and dishwashers have a lot of it.
Not only may it et at the rubber the heat that builds up due to the chemical reaction can exceed the rubbers designed heat resistance levels
Some dishwasher cleaning solutions may contain caustic soda (or others) but this will be designed to move around and drain before issues even get a chance to start.