brown water from hot tap only

Naughton4

We had our radiators flushed and fernox put in. There has been a huge improvement in heating but now water coming from hot taps is brown. All other taps in house are fine. Plumber came and drained whole system down then refilled but two days later back to brown hot water. Plumber tells me he doesn't understand why this is happening??
All advice appreciated.

jca

Was it a power flush? He's probably split the coil in the copper cylinder and the heating water is leaking into the domestic supply.

sky6

jca wrote: »

Was it a power flush? He's probably split the coil in the copper cylinder and the heating water is leaking into the domestic supply.

+1 Seems the most likely cause, especially if the Cyl is an old one.

KK4SAM

Might just be pitching and bring sediment down from the header tank ?

Naughton4

KK4SAM wrote: »

Might just be pitching and bring sediment down from the header tank ?

What does pitching mean? Also pressure dropping in boiler

KK4SAM

Sorry, pitching wouldn't cause it as the systems are separate .As earlier posts suggest the only possible link is the Cylinder coil.

jca

Naughton4 wrote: »

What does pitching mean? Also pressure dropping in boiler

With the pressure dropping constantly it looks like the coil has been damaged. Whoever did the flush must have let the system become over pressurised for some reason or the coil was on its last legs and the high flow through it as sent it to the copper cylinder graveyard.

Wearb

The systems might be seperate, but i have seen overflow from both tanks connected in a way that allowed for F&E overflow to contaminate DHW tank.

Anyway most likely as JCA said. Though I wouldn't have phrased it as he did. "He's probably split the coil in the copper cylinder" If the coil split, it was because it was already weakened. Power flushing doesn't damage a coil that is in good order.

EDIT:
I was posting at same time as you were JCA

DGOBS

Powerflushing is 'low pressure, high volume'

Dtp1979

jca wrote: »

With the pressure dropping constantly it looks like the coil has been damaged. Whoever did the flush must have let the system become over pressurised for some reason or the coil was on its last legs and the high flow through it as sent it to the copper cylinder graveyard.

Ye may straighten your words out. You cannot over pressurise water when Powerflushing. Powerflushing dosent cause leaks or burst radiators or any of that nonsense. It simply exposes a leak.
Op your cylinder coil is leaking. If your plumber could not identify that then I'd be looking for another plumber.

jca

Dtp1979 wrote: »

Ye may straighten your words out. You cannot over pressurise water when Powerflushing. Powerflushing dosent cause leaks or burst radiators or any of that nonsense. It simply exposes a leak.
Op your cylinder coil is leaking. If your plumber could not identify that then I'd be looking for another plumber.

I'm sure the op understood what I meant even if you didn't or are just being pedantic for the sake of it. No brown water before power flush...........brown water after power flush....I wonder what caused it If the water is still brown after the power flush that wasn't done properly either. It looks like the op needs both a new cylinder and a new plumber.

Dtp1979

jca wrote: »

I'm sure the op understood what I meant even if you didn't or are just being pedantic for the sake of it. No brown water before power flush...........brown water after power flush....I wonder what caused it If the water is still brown after the power flush that wasn't done properly either. It looks like the op needs both a new cylinder and a new plumber.

Ignorant statements like over pressurising and Powerflushing splitting coils in cylinders gives Powerflushing a bad name that's all.
But yes, the op does need a new cylinder and plumber.

jca

jca wrote: »

I'm sure the op understood what I meant even if you didn't or are just being pedantic for the sake of it. No brown water before power flush...........brown water after power flush....I wonder what caused it If the water is still brown after the power flush that wasn't done properly either. It looks like the op needs both a new cylinder and a new plumber.

I'v never known a powerflush to cause damage and it's unfair to those powerflushing to say their actions can brake a thing, now not spotting a defective coil is a different matter.

Naughton4

Thanks everyone for the replies. I'll get myself a new plumber and a new cylinder. We live in a standard 4 bed semi. How much do you think it'll cost?

Dtp1979

Naughton4 wrote: »

Thanks everyone for the replies. I'll get myself a new plumber and a new cylinder. We live in a standard 4 bed semi. How much do you think it'll cost?

Between 300-400 I'd guess

Wearb

Make sure to cure the problem that caused the need for the power-flush in the first place.

KK4SAM

Wearb wrote: »

Make sure to cure the problem that caused the need for the power-flush in the first place.

I have often seen heating header tanks above the domestic water tank,cross contamination will almost certainly take place with such a leak as the header is higher than the domestic.I the base of the tanks are at the level the top water level in the domestic will invariable be higher that the heating level resulting in feed water entering the heating system causing sludge build up.I never really thought about it as much.

John T Carroll

KK4SAM wrote: »

I have often seen heating header tanks above the domestic water tank,cross contamination will almost certainly take place with such a leak as the header is higher than the domestic.I the base of the tanks are at the level the top water level in the domestic will invariable be higher that the heating level resulting in feed water entering the heating system causing sludge build up.I never really thought about it as much.

One of the "advantages" of this (F&E higher than the CWST) was that as soon as the coil started to leak one would see the discoloration in the hot water as years ago quite alot of people (most?) didnt use Fernox inhibitor or the like. it quickly concentrated minds as any whites that were washed didnt stay white for too long.
Years ago a lot of people around here got their attics converted into a bedroom and had a rad fitted, any ones that I have seen have the F&E higher than the CWST otherwise it was very difficult to get rad circulation in the ones that were installed on the same level as the CWST. (In this set up the W.Level in the CWST is normally higher that that of the F&E tank)