Heating system from hell....

[leenowell]

Hi all,

I added a radiator to my sister's central heating system and fitted a bigger radiator in her utility room. I drained the system before doing the work then tried filling and bleeding afterwards. Bleeding was a bit of a drama as air was trapped and I eventually ended up letting the pump run for a little bit to get things moving.

Now the problem....

I have "successfully" bled all the rads - i.e. opening the vent valve produces water (rather than air or nothing in the beginning!) however am having a mixture of results with the rads...

- the upstairs ones in the front of the house are fine

- the upstairs ones in the rear of the house are very slow to heat up

- the downstairs ones are all fed from above with pipes running down the walls in each room. These heat very slowly and not to the temp of the upper one. Almost as if these are heat by heat transfer in the water/ pipes rather than hot water flowing through them.

- the utility room rad (looks like it is the last one on the circuit but not sure!) doesn't come on at all....

My theories and what I have tried...

1. there was an air lock - I have independantly attached the flow and the return of the utility room rad to the mains water and filled the system up from there. Still no impact on the rad.
2. Something wrong with the rad - I have connected the flow and return for the utilitty room rad together (bypassing the rad) still no change
3. I have let water run out of both the flow and return of the utility room until the water was hot (ie came from a "working" part of the system) Still nothing.
4. New valves are dodgy - disconnected each from the rad and turned on. Water flowing fine.

I am now at a loss of things to try.... All my money was on the air lock and connecting to the mains working... no such luck.

Does anyone else have any cunning plans????

thanks in advance for all your help

Lee.

[Harry Bloomfield]

[e-mail] brought next idea :

Have you tried closing all valves except for the valves on the radiotors causing a problem?

[BigWallop]

Are you filling the system without running the pump and re-filling the system after you have bled each radiator?

If you can, turn on the fill loop to a quarter of its full pressure, then go to each radiator and bleed it until you get all the air out. This may take a couple of minutes and a few bowls full of water, with a lot of spluttering also.

Once you are sure the that radiator is getting full water pressure, move on to the next rad' and so on. But you have to make sure you are drawing all the air out of the system at each radiator in turn.

Do this with just the fill valve on. No pumps running. No boiler on. Nothing. Turn the power off to the timer as well if you are not sure of the settings on it, just in case it demands heating while you are doing the bleed run.

Good luck with it.

[ransley]

What is water pressure, you have air somewhere, it could even be a high point on a main from the house settling. I would blead them again, check water presssure and wait, an air bubble can sometimes work itself out when water gets hot, dont add cold water to a warm boiler.

[TheScullster]

wrote

Other responders assume this is a pressurised system - can't see that in the original post. But, in any case....... Have you switched any zone valves in the system to the manual position ? There may be one three-way valve OR maybe one or more two-way valves. Moving these to the manually open position greatly improves the drain/fill operation.

Phil

[Slider]

Is it just a case of the system needs balancing as you have added 1 radiator and increased the size of the other? Close the valves on the rads nearest the boiler to let the other rads have more heat. Can the boiler cope with the additional rad and the larger other radiator?

[leenowell]

?- Hide quoted text -

One step further forward..... I was thinking about Scullster's reply and although I asked the question about zones etc. whilst I was there, there were 2 motorised valves in the airing cupboard one for the water and another one (I assumed the heating controlled one). Cutting a long story short, I got her to up the termostat downstairs and the kitchen one that operates the kitchen underfloor heating and hey presto, the rad strung to life!!!!

Next bizzare thing is that the rad heated slowly (about 20 mins) from left (normal valve) to right (TRV) and the pipe "feeding" the TRV remains cold. I fitted the TRV when I fitted the rad and although it claims to be bi-directional, I suspect that it is only working in 1 direction (I had proved it worked in the other direction over the weekend). Does this sound likely?

Feels like a wasted weekend but hey a solution in the end. I guess the next questionto answer is how exactly does her heating system work

- i.e. which thermostat got it going....