Is sludge worse in colder weather?

[mrbrunes]

Hi

My heating always stops working during a cold spell (coldest room is about 14deg) but it eventually "wakes up" and starts to work later in the day. The hot water is always fine. During warmer spells the heating seems to be OK apart from a couple of rads in the basement which only get slightly warm.

I have a Worcester Bosch Highflow 400 (not condenser) about 10y old and in a sealed system. It had Sentinel X100 renewed a few years back when I had some rads replaced. I suspect that there may be some corrosion because the system pressure falls below 1bar several times during the year and it needs refilling, which I gather can cause corrosion.

Also The Worcester boiler contract engineer, after he had recently replaced the diverter valve coil, said he thought that the system may need flushing as he suspected that the heating was shutting down due to resistance in the pipework.
I'm just puzzled though why the heating just stops in cold weather when it seems fine at other times. Any ideas on what should I do?

 

[John506]

Flush it out yourself, cold flush, hot flush, chemical flush. Doing them yourself can all be found on google.

At least you can then rule sludge out of the problem.

 

[arfurrrr]

err , some equipment is needed if you gonna try and flush it yourself .

plenty of examples here