Right, now I understand why you asked about deposit. I didn't realize that counted towards valid eviction paperwork.
If LL gives you the deposit back then I guess you have a tenancy without a deposit? So no need for a deposit scheme? Or does your tenancy agreement say you gave a deposit? He's offering you the deposit back, even though you're still there, because he's broken the law and (I think) owes you more than just the original deposit back. I don't know whether he'd have to put the deposit into a deposit protection scheme now to comply with eviction paperwork.
The gas safety certificates and electrical safety certificates are important too. He'd have to pay out for a new gas safety check so you've got a certificate, and that might fix that situation I think, unless he still has to show he'd complied all through the tenancy which he can't do, IDK. Agree with poster above, gas engineer would have given tenant a copy of certificate (which you as tenant would have signed) and sent another copy to LL. So has LL really had proper checks done by qualified person, if this hasn't been happening?
It could be that because of his mess ups he can't evict you. This doesn't mean you have to pay higher rent. You could refuse to pay more than you're already paying and he'd have to go to court to evict you somehow, maybe under some clause other than Section 21 if he's messed up too much to do that one, IDK.
I don't understand why you're so keen to move though. A good LL who does repairs in a timely manner, cheaper than average rent, a property without damp issues (since you haven't mentioned any)...there's no guarantee what you'd get from the council would be any better than this.
You can't stay in temporary homeless accommodation forever until your dream property comes up. Either you wouldn't want to because of the cost (if you're paying) or they won't want you to because of the cost (if they're paying) and also because of the size/inconvenience. All sleeping in one room or having to use a launderette and survive on takeaway gets old pretty fast. You'll be hassled out into any suitable property, eventually. Do you realise not everyone even gets a council property? The council also help people find private rentals that are affordable and help with deposit if tenant can't afford one. You can't choose and refuse all the private ones.
HAs don't always make good LL, you could end up with one that doesn't do any repairs if they can get away with it, a mouldy property that needs razing to the ground and rebuilding (that'll never happen), bullying or noisy neighbors, living in a totally different area to where you are now, in a permanent property you like less than this one. And definitely like less than this one for the temporary property.
Admittedly it'll give you a secure tenancy if it's a council property, although I think they may even be phasing these out now, but still more secure than the prospect of potentially moving on again every 6 months in private rental.
Anyway, whatever, you seem to think you can hurry along getting a council house. You can't. You've got an adequate and affordable roof over your head for now, I'd be grateful for that. You'll be evicted at some point in time, whether it's now or if the LL eventually sells up.
If the section 21 isn't valid then you're not being evicted so you're not homeless and your priority status for a council property will be reflected in that. You asked why the council hadn't changed your banding. This is why. They were checking the validity of the Section 21 first because as I said before LL often make errors (which yours has), it's not valid so no need to increase your banding or priority status, because you're not homeless.
I don't know where you'll stand with the council regards homelessness if you refuse to pay the raised rent. I know rent arrears (without good cause maybe?) can be seen as you making yourself voluntarily homeless. If the raised rent is still going to be below market value and if you can afford to pay it, I don't know whether that situation of being considered voluntarily homeless would apply to you. If it does, the council won't increase your banding or put you in temporary accommodation anyway. You'd be left to find another private rental.
I also don't think LL is going to evict you through the courts to do you a favour. (Are you somehow in cahoots and he has no need to evict you but you've asked him to because you want to use the homeless scheme?). Going to court costs money and is a hassle. If he doesn't need the flat back and you're paying the rent, why would he bother going to all the hassle to evict you? You're either homeless or you're not, OP. I don't think trying to pull a fast one (if that's what you're doing) is going to get you anywhere.
House is 3 bed large terrace for £500 a month Landlord does all repairs on time and all gas checks done etc. Kitchen was repainted last year so landlord nice enough but I want to move and have a garden.
This is fucking mental. You've got gold dust basically. And you want more.
You think council houses have gold plated taps or something? They can have dated décor too, kitchens so old and knackered that they're barely functional etc and there won't be any white goods at all including a cooker, you have to supply your own. You may or may not get a garden. If you do get one it may be communal, a patch of grass outside the row of houses, with neighbors peeping in your windows, sitting outside your open windows drinking, smoking weed and laughing loudly with friends all summer. If you can get by in a 2bed you'll likely end up in one and it could be a flat with no outside space not even a miniscule balcony. If you genuinely need a 3bed and would be overcrowded in a 2bed, you could be in temporary accommodation for ages because they're in short supply. Temporary accommodation won't be more than a 1bed flat, at best.
Permanent housing can also be great, but there's no guarantees.
You've not had a run of bad LL, constantly needed to move on, unable to afford anything that isn't damp, mental health shot to pieces by life and being made worse by your living situation. In which case there's a fair chance you'd be better off in a council place. But you - I'd stay where you are, pay the increase in rent, either improve your situation so you can afford something with a garden or else go back to the council when you're genuinely homeless and evicted from not being able to afford the rent or the LL selling up.