Flushing the system?

[vertical fool]

Have had Worcester engineer out today who replaced various parts, so now boiler (Worcester 24i with 13 radiators, all 8years old ) is working fine. He recommended a power flush as he could see sludge on the PRV that he replaced or at least some chemical flush being added.

So after reading previous threads I think I should try a mains water flush myself.

After reading the thread //www.diynot.com/forums/viewtopic.php?t=38902&start=0&postdays=0&postorder=asc&highlight= I`m a bit confused.


My boiler has the following connections labelled;


Safety Discharge : CH Flow : Domestic Outlet : Gas Inlet : Domestic Inlet : CH Return


Theres a filling loop from the domestic inlet to the CH flow


After reading the flushing post I assume I use the filling loop to force water into the CH flow.


This water will then be pushed around the system.


I exit this flow where? I don`t have a drain port. Can I undo the CH return and use this as the poit where I drain? (Question 1)


Closing the boiler circuit


Here I must stop the water from going through the boiler. I do this with the valve that is just after the CH flow pipe? (Question 2)


Drain down Rads

I don`t know how to do this. How do I drain the radiators?(Question 3)


Flushing Procedure

We are now ready to flush. First the discharge valve is opened followed by the filling valve. If the filling connection is to the return pipe, the boiler pressure gauge can be observed and the pressure limited to say 1 Bar to start with and then 2 Bar when you have more experience with the process. Initially the water will flow through all the radiators (subject to rad valve settings).

What are the discharge valve and the filling valve? (Question 4)

At the end of the process, you can reverse the fill and discharge connections and repeat the whole process in reverse. This will dislodge even more sludge.

How do I reverse these connections? (Question 5)

Finally, when the process is complete, you should briefly flush through the boiler itself (return to flow direction) and then refill the system.

How do I flush through the boiler itself? (Question 6)

The system can be vented and run as normal for a week or whatever period is recommended by the chemical cleaner manufacturer.

How do I vent the system? Can I vent the system when its a combi boiler (I assume its a sealed system)? (Question 7)


I look forward to your replies.

Thanks

Vertical

 

[chrishutt]

Jeez, a lot of questions.

1. If your filling loop connects to the CH flow pipe, you will need a drain connection on the return pipe.

2. You should have isolating valves just under the boiler where the CH flow and return join. Close one of those (but don't blame me if it leaks).

3. If you find a point at the bottom of the system to drain, then open the air vents on the rads, you can drain them of water.

4. The discharge valve is the one that you have fitted, if you follow the instructions given. The filling valve is usually the filling loop.

5. Change the hose connections over.

6. Open the valve that was closed - see 1. above.

7. Open the air vents on the radiators until water emerges.

 

[vertical fool]

Thanks Chris

Sorry, even more questions!

1. If your filling loop connects to the CH flow pipe, you will need a drain connection on the return pipe.

Can I disconnect the CH Return and then use a hose/tubing on that? (Question a)

3. If you ind a point at the bottom of the system to drain, then open the air vents on the rads, you can drain them of water.

There doesn`t seem to be a drain valve. Can I drain the through disconnecting one of the ground floor radiators? (Question b)

4. The discharge valve is the one that you have fitted, if you follow the instructions given. The filling valve is usually the filling loop.

Do I have to fit one of these? Can`t I use the existing connectors? If I do must this be brazed on? (Questions c)

6. Open the valve that was closed - see 1. above.

So then the water will take the shorter route through the boiler? (Question d)

7. Open the air vents on the radiators until water emerges.

So

The system can be vented and run as normal for a week or whatever period is recommended by the chemical cleaner manufacturer.

The venting of the system is just temporary until all the air is out (the same as saying bleed all the radiators). The system is then run with the vents closed for the rest of the week. Correct? (Question e)

Thanks

Vertical

 

[chrishutt]

a = yes

b = yes

c = read original post. It suggests using compression fitting, so no brazing or even soldering. I get the feeling that you don't really grasp all this - maybe you shouldn't attempt DIY flushing?

d = yes

e = yes

 

[vertical fool]

Thanks Chris.

It suggests using compression fitting

The compression fittings didn`t register with me until you pointed it out. Information (or question) overload. I`ve had to go into question mode on here instead of the usual think for myself mode. However me going into question mode is better than my natural mode of trying to figure it out myself!

How easy is it to use a powerflush?

Maybe you could do a guide to using these?


Anyway, Thanks again Chris.

Vertical

 

[Fluffster]

Powerflushing is not difficult however to get it done right ie correct method for particular system, chemicals, and testing of water at the end.
Different powerflush machines have slightly different operational use such as double dump valves etc.

Use someone who does them regularly and is competent.

I attended a half day course with Kamco which was very informative and enlightening.

Having ago yourself depending on your competency may result in damaging the system or not cleaning and protecting it to its maximum potential.
Cleaning up magnetite (sludge) is not easy as it stains very deep even on concrete.

Average cost is about £350 for a 3 bed house including chemicals
Pete