Hi All,
I have a combi boiler and live in a hard water area. I don't have any problems...yet. However, I'm rolling around a few ideas as to what to do when the boiler eventually needs descaling.
I'm not worried about the CH side of things; that's only got a limited amount of water in it and therefore a limited amount of calcium, thus limescale build up shouldn't be an issue.
I am more concerned about the HW side, though, in particular scale build up in the HW heat exchanger.
I have attached a very rough sketch of what I'm thinking of..
A 'hippo' pump would sit in the kitchen sink, which would be filled with suitable descaler.
The hippo pump would attach to the cold feed to the boiler using a flexi-hose and probably via an existing cold washing machine valve under the sink. The main stop tap on the main would obviously be off when flushing and the boiler would be 'off'.
The hot tap over the sink would be open, thus allowing the descaler to enter the sink and then be sucked up by the hippo pump. I'd probably leave the thing running for an hour or so, on a fairly low flow rate.
Can anyone see any issues with this? The beauty of this (For me) is that it can be done using things I already have and there are no mods needed to the central heating system.
The heat exchanger is stainless steel and the system has had a "phosphate" doser on the cold feed. I'm still concerned that there will eventually be limescale build up as the doser isn't always filled up.
(Note that the boiler would be 'off'; the red and blue lines indicate what would normally be 'hot' and 'cold' pipes when the system is normally running)
I have a combi boiler and live in a hard water area. I don't have any problems...yet. However, I'm rolling around a few ideas as to what to do when the boiler eventually needs descaling.
I'm not worried about the CH side of things; that's only got a limited amount of water in it and therefore a limited amount of calcium, thus limescale build up shouldn't be an issue.
I am more concerned about the HW side, though, in particular scale build up in the HW heat exchanger.
I have attached a very rough sketch of what I'm thinking of..
A 'hippo' pump would sit in the kitchen sink, which would be filled with suitable descaler.
The hippo pump would attach to the cold feed to the boiler using a flexi-hose and probably via an existing cold washing machine valve under the sink. The main stop tap on the main would obviously be off when flushing and the boiler would be 'off'.
The hot tap over the sink would be open, thus allowing the descaler to enter the sink and then be sucked up by the hippo pump. I'd probably leave the thing running for an hour or so, on a fairly low flow rate.
Can anyone see any issues with this? The beauty of this (For me) is that it can be done using things I already have and there are no mods needed to the central heating system.
The heat exchanger is stainless steel and the system has had a "phosphate" doser on the cold feed. I'm still concerned that there will eventually be limescale build up as the doser isn't always filled up.
(Note that the boiler would be 'off'; the red and blue lines indicate what would normally be 'hot' and 'cold' pipes when the system is normally running)
