Draining

[tiko]

I have a small 2 bedroom bungalow, with an oil combi (wallstar) that is located in the garage. There is a lot of sludge (I believe) in my radiators as they are cold at bottom and hot at the top. In reasearching how to deal with this, I have seen many people recommend using Sentinel x800 to clean the system. But in order to use it, I need to know how to drain and refill the system. I think I know how to refill, as that is just a case of opening the filling loop valve until the required bar value is met. But draining, I'm not quite sure. From what I have read, you need to locate the drain valve (one for each drop), open it until it stops draining, and then go around opening up all the bleed valves to make sure you've drained the entire system.

The reason I'm a little confused though is due to the way my pipework is setup. I have the flow/return valves coming from the garage and then into the loft. From the loft, there is flow/return pipes down to each room, like in the diagram below.

But as shown, I only seem to have one drain valve (kitchen). Which I assume, due to gravity, is only going to drain the kitchen radiator/pipework. What about the water in all the other rooms? and also the water in the pipes in the garage? I was expecting a drain valve for each drop (i.e where water can't flow up due to gravity), so in my case, that would be each room?

Or do I have this all wrong?

 

[joni os]

You are basically correct, however, on your closed system, water will not flow out unless air can enter the system. This will allow you to drain one additional radiator other than the one with drain point. To do this, open drain point, then air vent at radiator you wish to drain. Normally the largest radiator will be chosen. Other rads can be drained individually with water collected in container such as 2 litre milk carton cut to shape. Just slacken nut at rad and control flow by hand tightening or loosening nut. With pipework in drops from ceiling, flexibility should allow nuts either side of rad to be slackened and the rads lifted off bracket, rotated to floor and removed completely, carried upside down, once small amount of water from pipes has been dealt with.

 

[tiko]

Thanks. What about the water in the garage? i.e the water in the pipes leading into and returning from the house to the boiler?

 

[joni os]

Thanks. What about the water in the garage? i.e the water in the pipes leading into and returning from the house to the boiler?

Disconnect fill hose boiler side of non return valve. When refilling you may well have air vents in loft that need manual opening, also ensure pump is vented by slackening large central screw.