Brown tinge to hot water when back boiler is on?

RTNI

Hi everyone,

I have recently moved into a new house and we have had the fire on over the weekends when the weather has been cold and noticed an issue with the back boiler and the hot water.

When the fire is on and the water heats up, the hot water out of the bathroom and kitchen tap runs a slight brown colour - noticeable when filling basin for dishes or washing hands in bathroom etc....

We don't think the fire has been used in about a year to 18 months (guess?). There are 3 pipes going into the side of our hot water cylinder, 2 for the boiler coil and one for the back boiler which enters the tanks above the boiler coil pipes. We can't feel or see another pipes so it's a direct feed for the back boiler and at the moment have not looked to see where the feed end of the back boiler is. We assume it's tee'ed off from somewhere but have not looked as yet.

Does anyone know why our water would run brownish when the fire is on but clear when the oil boiler heats the water? Is it rust/sludge in the pipework from the back boiler to the hot water cylinder? My big fear is that they have tee'ed the supply to the back boiler off a radiator but I don't think anyone would do that would they?!?

Had the fire on about 20 times since moved in from September time - can also hear the water "boiling" and bubbling up the expansion pipe in the hot press once every few hours but I guess that's just to do with the water getting heated so much.

Any replies most welcome!!

Thanks!

Razor

Does your cylinder have a label on in that says Primatic or 'single feed direct' by any chance? How many tanks do you have in the loft, one or two?

Or if the cylinder just says indirect on it you may have a split in the cylinder coil.

farmerboy

We have a back boiler behind our open fire, and occasionally have this issue if it hasn't been used for a while. I think its just basic rust, don't think it'll be t'eed into the CH system. Once we've used it the water clears, and no probs till the next time its been stood a while.

RTNI

Razor wrote: »

Does your cylinder have a label on in that says Primatic or 'single feed direct' by any chance? How many tanks do you have in the loft, one or two?

Or if the cylinder just says indirect on it you may have a split in the cylinder coil.

Can you give me any idea where I would find the label? I have the cylinder wrapped in 2 hot water jackets so any advice where to look would be great!

Have 2 tanks in the loft - one cold water for the toilet/bath and feeding the hot water cylinder and another small header tank for keeping the rad's topped up. The smaller one has a dark brown colouor to it so I assume that's some sort of inhibitor in it.

Why would a split in the boiler coil after the water when the fire is on? When the boiler is on the hot water is as clear as anything.

Razor

Sorry but your original post was a bit confusing!

So you have a solid fuel circulator behind the fire and a seperate boiler both connected to the cylinder?

RTNI

Razor wrote: »

Sorry but your original post was a bit confusing!

So you have a solid fuel circulator behind the fire and a seperate boiler both connected to the cylinder?

Yes, I have an oil boiler that feeds a coil in the cylinder and an open coal fire that has a back boiler that we are pretty sure is a direct feed into the cylinder.

Thanks.

Razor

If the back boiler is directly heating the water in the cylinder than the rust is probably coming from the cast iron heat exchanger, longterm solution would be to decommission the boiler whilst leaving the fire working.

This would best be done professionally as it involves capping off some awkward size pipes at the cylinder and disconnecting the boiler correctly to avoid any risk of future explosion!

RTNI

Razor wrote: »

If the back boiler is directly heating the water in the cylinder than the rust is probably coming from the cast iron heat exchanger, longterm solution would be to decommission the boiler whilst leaving the fire working.

This would best be done professionally as it involves capping off some awkward size pipes at the cylinder and disconnecting the boiler correctly to avoid any risk of future explosion!

Yes I thought it was just dirt in the pipes that had settled but I would have expected it to have cleared by now. Thanks for the advice and help!

Razor

It takes a very small amount of rust to discolour water as long as you're not drinking it you'll be fine