Plumbing - accidentally drained CH system!

[TiddleTaddleTat]

So DH found a tap outside the house and, not knowing what it was, turned it on until all the dirty water had come out...
It was a tap the previous owner had installed to drain the radiators etc. I knew about this but had neglected to tell DH.
Anyway - the boiler is clearly no longer working. It's a new combo boiler and was trying to run while this system was drained.
I followed the instructions on the boiler (was at 0 bar) and have fed in more water so it's now at 1-1.5bar. But still displaying a fault due to a lack of flow??
I don't want to call the plumber back (are mid renovations and he's only recently installed this boiler).
Any advice for a newbie please?

Combi boiler, that is

First things first - have you reset it?

Is there some kind of a reset button on it? Feeding more water into it should have worked but perhaps it takes time to work around? You need @PigletJohn

I couldn't find the reset button but switched the power off then on again, it seemed ok for a short while after adding more water but then fault again

It's a no water flow fault.
I guess we need to add water back into the CH system somewhere?
Gawd we're a big clueless...
So angry with DH!

if it's a pressurised radiator system, it might not have "emptied" and got air in it, because once the pressure has dropped, there is nothing to make the water drain out.

If you have refilled it to the correct pressure (1.5 sounds OK) and reset it (there is probably a reset button but the instructions will say) I'd expect it to restart.

You could turn on the central heating and let the pump send the water round for a bit. Any air bubbles will tend to be blown out of the boiler and collect in radiators. Turn the boiler temp right down while you do that, if after half an hour it seems OK, turn the heat up to normal (this makes any air bubbles expand so watch the pressure gauge in case it goes up too much when hot)

You say the water that drained out was dirty. It would no harm to give it a chemical clean and then refill with clean water and corrosion inhibitor. If you are not a plumbing enthusiast you can get a plumber or boilerman to do it (it does not require opening or touching the boiler).

Have you got a system filter such as a Magnaclean?

Thanks @PigletJohn I'm a bit freaked out by the idea the pressure might get too much! A quick google suggests we should bleed the radiators to release air bubbles first before adding more water to the boiler?

The fault code detail says :
Operate heat exchanger manual air vent (use hose).
Check isolation valves.
Fill system to 1 bar then vent and refill.
If fault only DHW, check plate HX.
If fault persists replace pump.

Oh and the plumber still has 2 rads to fit so he has some of the anticorrosion stuff and said he'd put it in when the last rad was installed?

We have just had to take a radiator off the wall and then put it back.

Have you bled all the radiators to make sure there is no air pockets and the radiators have filled up.

Then we pressurised the boiler and it worked.

@Oliversmumsarmy does feeding the water into the boiler refill the radiators too? Sorry - clueless.
No we haven't done that yet but am pondering. Is this an easy fix ? Don't want to end up with a leak etc when we should just call the plumber back.

Ok going to try bleeding the rads and will let you know how we get on...

the water in the boiler and in the radiators is the same. It does not mix with the tap water.

If the pressure gets too high, it will vent out of a pressure release valve. The exit pipe usually goes through the wall behind the boiler. This should be avoided as it will wet the outside wall and may stain. In your case i think it is unlikely to happen.

Bled all radiators as per boiler instructions, then refilled to just over 1 bar and same fault reported - water flow fault.
Balls! No hot water

Now trying PigletJohns method with running the central heating... first time round it gave us another fault message then massive gurgles and rushes of water to the radiators... they are now warming up.
Thanks for all the help - appreciated

have you tried putting the radiators on?

too late....

Thank you @PigletJohn
Looks like it's all working now. Running the CH for half an hour seemed to get rid of the air bubbles and then the hot water started working again.

Definitely an air lock but most folks don't know how to vent/bleed properly and without a filling loop, you can't top up the system at all.
However, it's very odd the Plumber is not available to talk to or visit to resolve this as you say he still has CH work to do.
Albeit not your fault in the system failure as all you've done is open a drain valve which is handy to have when working on CH, so the Plumber needs to cap it off and put a drain valve on a rad, ideally near an open waste outlet i.e a sink or bath for future work. Now is the time to get this done.
Ask your Plumber how to correctly bleed the rads as per your system. You can't expect anyone in the world to know your property as well as someone who's worked on it, so asking advice of amateurs and mums (no disrespect, most women are not plumbers or engineers) is not wise.
You may argue you got the problem resolved, however, you have now emptied the inhibitor (chemical radiator rust protection) by draining the CH water, so if the Plumber wants to, he can void his guarantee or even the contract as you've interfered with his work which you will want him to guarantee.
So my advice to anyone who gets this issue is to call your tradesman first before you do a thing. Even if he is not responsible for the issue. He doesn't expect you to know what to do in the event of an issue and you are not obligated to attempt it yourself unless it's specified in a contract (which it never is).
I do agree in your angst at whoever turned the tap on, however, it's not their fault either as this shouldn't be a tap valve at all, it should be a square metal valve that only plumbers can open, so now you know how to avoid this happening ever again.
In the meantime, tape that tap!

Moral of the story: ASK FIRST!

Thanks @Neverbuyretail agree , and I will be talking to the plumber tomorrow.
Issue was more that it happened on a Saturday night and we wanted hot water etc.
The issue is also that we decided after the plumber was last here that we would get a quote from someone else as the plumber we have used is really bad tempered and can be quite rude, although we are happy with his work he sometimes tries to claim for additional materials etc. Basically he takes advantage.
He did specifically say that the chemical inhibitor would need to be added to the system once the last rad had been installed. There are two still to go - the reason they haven't already been done is that the my are column rads and we want to paper and pint behind them.
Is there a certain timescale we have , now that there is no chemical in the system ? Or is it just ASAP ?
I will use the same plumber if as you say it is preferable to have the same person who knows the system (and has prepared the pipework for his return) .

That's it...there's always something hidden somewhere!
It is disappointing to hear that you don't have an ideal Plumber, we are gold dust these days more than ever and most of us always go for quickest and highest paid work.
I have found miserable Plumbers and happy ones and the reason they are miserable is usually a personal issue, not because they hate their job unless they are injured in which case working is actually painful which no one would be happy about. It's not a job for everyone either which is why this trade suffers numbers.
Overweight or just big people cannot be Plumbers for example. And the knowledge is vital so it requires good brain skills too.
A good Plumber is a good problem solver.
That's a good way to identify a difference in choosing a tradesman. Some will just throw your money at it, others will try and save you money to build trust.
It really depends on the professionalism of the person you are dealing with.
Personally (if I were you), Id find another plumber if you have more than 1 issue with the current one. Then, aim to use them regularly. Have them finish the work (get those walls sorted!) and pay what they ask if they agree to service you regularly and are willing to have an agreement in place. You can save on paying VAT on labour if you choose a smaller independent, so look out for vans that aren't too corporate looking and have mobile numbers.
Ask them then to schedule a quarterly visit (which you'll pay for) for them to assess your property for any potential issues and conditions of the appliances and pipework. Look at what you spent last year on maintenance and you will see you have a high amount in fact. Few people do this and it's the same as saving on your electric bill by using less.
You then negotiate an annual deal of 4 visits regardless of what might or might not need doing. This is being pro active rather than reactive and is currently only a method (very effective) that exists in commercial maintenance. I used to maintain Canary Wharf tower with a client of mine.
I offer this service myself but I'm on The Isle of Wight so I'm geo limited.
But if anyone is reading this who lives or has property here, I can help you with every aspect of your home and you can imagine how short we are down here of tradesmen considering we're a 25 mile island!
Diamond dust? : )

Don't be too hard on the tap turner will you! : ) Just a few lashings will do!