Hi, first time here after inheriting a 2011 Polo. Unfortunately, there's no heating in the cabin.

Trying to take a systematic approach to it; I've confirmed all fuses that are fitted are ok (incidentally main beam wasn't working; I found fuse 34 missing, replaced it and they're now working ... I don't know how this thing got through MOT).

I'm working from https://polo.blue/fuses-and-relays-in-polo-6r/. I believe I'm looking for the low and high output heater relay fuse(s). That's fuse 20, and that's ok.

Going to the relay box though ... I don't seem to have relays (or anywhere to plug them in) in positions 1 and 2. Looks like I have 30V supply (643) at 3, dipped beam (449) and fuel supply (404) at 4, fuel pump (449) at 7 - and then what looks like the x-contact relief relay (100) at 10.

I tested the x-contact relay and that seems fine.

Before I start taking things apart am I barking up the wrong tree?

Thanks!

I expect only the diesel engined cars got the additional electric heater that those (absent) relays control.

Do you mean that the cabin blower doesn't work, or just that there's no heat in the incoming air, even with warmed up engine?

Cabin blower works, but there's no (noticeable) heat to the incoming air, even with a warmed up engine.

Could be a fault with the flap motor which controls the proportion of incoming air that gets routed through the heater matrix.

VCDS scan of HVAC module should report a fault code relating to that if so.

Thanks @Pete1 - I've got a generic obdii reader but looks like that's not going to pull the codes out?

That's a good starting point though, I'll have a dig around and see what I can find 👍

Not sure if it helps, but within VCDS the module you want to read for fault codes is labelled 08- Auto HVAC. It may be similarly numbered or described in other fault reader systems.

The specific item is known as V68 "Temperature flap control motor".

See here for a possible fault code and diagnostic suggestions:

01271 - Ross-Tech Wiki

Thanks for the info @Pete1.

I went back to basics and bled the cooling system first, and found that the input heater hose got hot and the output stayed cool. I figured it was the heater core, so I took the hoses off and flushed it out with water, reattached the hoses and now I have heat, enough at least for those mornings hovering around 0.

Am pretty sure I need to drain the whole system and refill it though, there was a LOT of gunk in there.