Calchem for me. 
Always carry a couple of bottles.
Always carry a couple of bottles.
I would also recommend the Sentinel 100 as inhibitor. With Fernox chemicals if Sentinel is not available.
Considering the cost of a heating system I really wonder why so many people put in cheap ( unknown ) chemicals.
All my boilers get x100.... others dont
What do you mean "others dont"?
If I had a bottle of X100 and had other inhibitor from another brand already in the system, whilst it may be better to stick with the same brand, is there any danger to using and topping up with a different brand?
On an unrelated question, if I need to have my plate heat exchanger changed, will the gas engineer have to drain the whole system or I guess there must be some isolation valves on the boiler or near it which will allow him to change it without draining the system>
Normally plate is blocked on CH side not DHW. Some magic in a bottle usually clears it. Plenty of flushing after and if particularly fouled up, a visit to my friendly mechanic for a special bath does the trick (make of that what you will!).
I am very surprised they have agreed to replace the plate HE as the blockage was not related to it.
I normally just remove the plate HE and clean it on site all in one visit. Far cheaper for the client as I can do it quickly in just one visit without ordering and returning with a new one. My cleaning deals with oxide dirt as well as any lime scale.
Lime scale is not normally any problem in London unless there are dripping hot taps. However, the water to the west of London is far harder and in those areas significant lime scale can be deposited in plate HEs. I have even been to some in Reading with the flow reduced to virtually zero.
Special liquid is what?
Special concoction of chemicals that I'm not going to document in writing, with my name attached, here or anywhere.
The bath I refer to is a sonic bath.
A power flush will not in any way clear limescale from a plate heat exchanger, the two waters never meet, a power flush filters and cleans the primary water (system water) this heats the secondary water, the water that comes out of your taps, the two waters never meet unless the plate heat exchanger pinholesWhat would you normally charge to flush a heat exchanger?
Lime scale is a huge problem in London where there is hard water - why do you think it’s not a problem?
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