Questions About Flushing

[xdavid]

I just cleaned out my DHW heat exchanger to fix a reduced flow problem in the hot water (all nice and hot-hot now). The amount of oxides (no sludge, just rust-like flakes and particles) which came out of the heat exchanger suggests to me that a good flush of my system would be recommended. Sound correct so far?

After reading old threads in the forum (really useful) I've a couple of questions…

Q1: If this is a 'closed system' (combi-boiler, Excell 80SP) then is the presence of oxides just because I have not been dilligent at getting the 'inhibitor' renewed? I've not done it in my 6 years here and other posts seem to suggest it should be at least checked every two years? Or do closed systems need a full flush every so many years anyway?

Q2: If a full flush is needed, how long should I expect a plumber to take for 5 rads? I've read some horror posts about 'cheap' half-done jobs so how much time should I expect for a good job?

Q3: Are the magna-clean type things recommended for a small system like mine? (Likely part micro bore - full description below). They seem quite expensive. Is their main benefit to protect the boiler? I'm thinking maybe modern boilers have finer main heat exchanger pores so more prone to blockage by fine particles and since I'm thinking of getting a new boiler this year maybe I should get a magna-clean thing installed beforehand?

Thanks in advance for comments!

System Description: Boiler is a Vokera Excell 80SP, maybe 8 years old (maybe 10?), feeding 5 steel rads (single storey ground floor flat). Living room rad has 15mm flow/return and rest have 9mm (copper). Don't know what is under floor (timber joisted, but no easy access) but presumably micro-bore coming off flow/return to living room.

 

[Blackcatgas]

I just cleaned out my DHW heat exchanger to fix a reduced flow problem in the hot water (all nice and hot-hot now). The amount of oxides (no sludge, just rust-like flakes and particles) which came out of the heat exchanger suggests to me that a good flush of my system would be recommended. Sound correct so far?

After reading old threads in the forum (really useful) I've a couple of questions…

Q1: If this is a 'closed system' (combi-boiler, Excell 80SP) then is the presence of oxides just because I have not been dilligent at getting the 'inhibitor' renewed? I've not done it in my 6 years here and other posts seem to suggest it should be at least checked every two years? Or do closed systems need a full flush every so many years anyway?If in those 6 years youve been regulary topping up the system with fresh water then yes you need to check it yearly, its so easy to do. A non leaking sealed system with the correct amount of inhibiter added will not need a flush, probably ever.

Q2: If a full flush is needed, how long should I expect a plumber to take for 5 rads? I've read some horror posts about 'cheap' half-done jobs so how much time should I expect for a good job?Takes me on average 6 hrs to do "properly" but Id charge for the full day,

Q3: Are the magna-clean type things recommended for a small system like mine? (Likely part micro bore - full description below). They seem quite expensive. Is their main benefit to protect the boiler? I'm thinking maybe modern boilers have finer main heat exchanger pores so more prone to blockage by fine particles and since I'm thinking of getting a new boiler this year maybe I should get a magna-clean thing installed beforehand?They are a fantastic product, I spec one with every boiler install I do now, Getting one fitted before your new boiler will only do good IMO.

Thanks in advance for comments!

System Description: Boiler is a Vokera Excell 80SP, maybe 8 years old (maybe 10?), feeding 5 steel rads (single storey ground floor flat). Living room rad has 15mm flow/return and rest have 9mm (copper). Don't know what is under floor (timber joisted, but no easy access) but presumably micro-bore coming off flow/return to living room.

.........

 

[xdavid]

Thanks, Blackcatgas. I've been reading up on the Magnaclean and looks well worth it.

I'm now thinking that I'll fit a Magnaclean myself soon and leave the full flush until the new boiler gets fitted (probably summer). That way, the plumber can do the whole job and and is able to 'certify' whole system - looks like some boiler guarantees are not fully valid without this (understandable). Also, the Magnaclean will allow me to easily add an inhibitor just now since my system obviously needs it.

Does this sound sensible?

 

[LIFES A GAS]

The Magnaclean is worth fitting as it works very well, dont go for the cheaper Boiler Buddy from Fernox, it's much more difficult to clean out as whoever designed it did'nt have a clue as the iron oxide sticks directly to the magnets and as you brush it away from one part it attaches to another part, the Magnaclean has a plastic sleeve which slides off of the magnet, you just need to rince under a tap & refit
Martin.