baxi duo tec 40he flushing?

[nat110732]

Hi,
I am in the process of fitting a new bathroom, swapping the existing rad for a towel heater and add a couple of small rads elsewhere in the house and thought that i would drain and flush the system while I'm at it. Unfortunately the plumber neglected to put a drain valve anywhere?
Is there a sequence of draining the system without a drain valve? Or is it just a case of cracking the rad nearest the back door and hastily fitting a hosepipe to it?
Also when flushing the system out is it just a case of adding the cleaner or can you attach a hosepipe and continually flush the system until it runs clear?
The combi is a Baxi duo-tec 40 he and we have 10 rads on the system including one in the attic bedroom then 4 on the first floor and 4 on the ground. I plan to add a small rad in our back porch and another small one in the loft which is fully boarded and insulated (gonna be a future man-cave not sure if any of this is relevant but I thought I would include it anyway just in case

Thanks for looking

Regards Nat

 

[nat110732]

Also would cleaning the system out run the risk of sludging up the boiler?
The system hasn't had any cleaner or inhibitor for 7 yrs that I know of so not really sure of my best plan, any advice would be greatly appreciated

many thanks

nat

 

[PullerGas]

If the Combi is not old you could 'crank' the system & fit a D.O. type valve on the radiator that's sited near your back door.

To crank; switch off your system, let it cool down, turn off the F&R valves at the combi, turn off the other valve at the radiator, tray under the valve you're replacing - there will be a little water. Remove the valve & fit the DO valve, turn on all valves & bleed radiator, top up if required.... Job done!!!

 

[nat110732]

Thanks PullerGas for the reply fortunately the rad nearest the backdoor is the smallest and a single!
The combi is 7yrs old so not sure if that's too old though..

Many thanks for taking the time to reply

Cheers Nat

 

[PullerGas]

Thanks PullerGas for the reply fortunately the rad nearest the backdoor is the smallest and a single!
The combi is 7yrs old so not sure if that's too old though..

Many thanks for taking the time to reply

Cheers Nat

Why would that matter when you're only fitting a doc?

 

[nat110732]

Not sure what you mean 'why would that matter'..do you mean that the rad is 'small and single' or that 'the combi is 7 years old'?
If you mean the rad, I was just glad that not much water would drain out compared to a large double rad.
You said 'If the Combi is not old' , I was just saying how old it was

Cheers nat

 

[PullerGas]

Not sure what you mean 'why would that matter'..do you mean that the rad is 'small and single' or that 'the combi is 7 years old'?
If you mean the rad, I was just glad that not much water would drain out compared to a large double rad.
You said 'If the Combi is not old' , I was just saying how old it was

Cheers nat

You've created a vacuum in the system nat, the radiator will not drain. There will only be a very short blast of water & then it'll stop..........

 

[nat110732]

Thanks PullerGas

I see what you mean now !!

Is there a preferred method of adding system cleaner and inhibitor to a system or is it just a case of following the manufacturers instructions? I am really concerned about the possibility of washing loads of s**t into the combi, especially as winter is upon us! Are there any particular brands that come recommended, do you'get what you pay for' or are they much the same?

Thanks for taking the time to post your advice

cheers nat

 

[PullerGas]

Nat. You need to check the PH level & PPM of the system water for that. There's loads of snake oil when it comes to inhibitors etc. I like the Fernox range.

For adding chemicals, isolate one largish radiator & add it to that one. Tomplum has several excellent videos on YouTube regarding how it's done.
HTH

 

[nat110732]

PullerGas

Thank you, just googled the 'chems' and I see what you mean about 'snake oils' and 'magic potions'!!

I will look into the Fernox range and check out the Tomplum vids

Thanks for all your help

Nat