Issue with one radiator in open vent heating system no flow

Slow down ... not sure if you remember (read back on the posts) but I mentioned that to using a pressure tester to clear blockages/restrictions was a last resort and that you really need to get to both ends of the pipe that way the pressure can be built specifically in the pipe that's restricted and then used to blow through it under pressure. Now that the pipe is flowing then it's not blocked anymore rather restricted and that process may not be as effective. Even then you don't want to put the whole system under that pressure especially if it is gravity fed. When I recommended the pressure tester was when there was little or not flow. That has changed and now there is flow so the tester may not be needed now and the cleaner may be enough.

If you can work on that pipe specifically then that would be the way I would go.
Sponsored Links
OK understood. Will get the filter on and get some x800 back in and run it for a while before cutting into the pipe at a point where I have access.
Using the X400 is less aggressive therefore it can be left to run in the system for a week or 2. That way the system can go through lots of heat cycles etc and that can greatly assist the cleaner to eat away at the restrictions in the system whilst the filter will sift out the magnetite and solids.

X800 is great for pro's who want to in and out in a day or 2 as it's that aggressive but it needs to be used that quickly and then fully flushed out to stop any long term issues from the cleaner.
Hi plan is to try and get some more flow with the x800 and then flush that out and then leave x400 in the system with the filter dragging the suspended particles out. It is a property I rent out so need a quick fix if I can without too much disturbance. If it was in my own home would be much easier rather than going round there when I can. Current status is that there is hardly any flow with radiator just slightly above ambient according to tenant. However I will be better judge when I get round there. Thanks
Sponsored Links
Why are you, as a landlord, not getting proffesionals in?
it would be best to divert the solids away to somewhere else by opening up one of the pipes at a suitable location if possible. the solids have to go somewhere, if that is elsewhere in your existing piping then that will mean more cleaner used up to slowly dissolve it.
Why are you, as a landlord, not getting proffesionals in?
I provide decent quality accommodation at a good price. Unfortunately margins took a hit since covid and stealth taxes by government / local authority.
Thanks @Mike13 . Fitted the filter today and got some floor up on the 1st floor. It has been very poorly piped with 15mm on main runs rather than 22. The run towards the front of the property serves 2 rads downstairs one 2m long one 2.2m and two up stairs including the bad one with compression T that splits the 3rd bed and the bad rad with everything else being soldered. Was going to undo this and give it a blast with the bucket tester but this was a fail as the cheapo bucket tester 15mm pipe would not go in the fitting or thinking about it maybe not 15mm as it would be imperial. Pipe to the bad rad does get hot when I have the other rads on and lockshields in a certain position. So have filled with x800 turned boiler flow down and left heating on.
I provide decent quality accommodation at a good price. Unfortunately margins took a hit since covid and stealth taxes by government / local authority.
Is it no longer viable as a business?
Do you do the other building maintenance stuff like electricity, building, etc?
Just about viable at current rate which is below market rate. All electrics signed off and LL licence (sorry I mean tax) in place. Prefer to keep tenant rather than bring inline with market rate as better the devil you know.
Will go to local plumbing shop and pick up 1/2 inch bsp to 15mm Bush adapter and hopefully when I undo the compression I can clear the poor flow with the bucket tester.
Hi all, I am draining out the x800 today and have an observation. I am using the tf1 to drain the system and if I close the flow valve or the return valve on the offending radiator then the system stops draining. Does that indicate anything?
Last edited:
Have left the system with cal-chem inhibitor / cleaner in and will see if the situation improves beyond the flow pipe getting hot. Will address after the holidays to save the turmoil of lifting floorboards etc.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links