Would a new boiler be OK in a very old C/H system ?

[Brian Lacey]

We live in an old cottage that has very old c/h and boiler but it works. It does 'what it says on the tin' it heats the water and keeps the place warm. The boiler is a Vulcan Continental, at least 35/40 yrs old but serviced every year and works fine. Maybe not "green" efficient but it is reliable. The 10 old, double paneled rads are the same age, but no leaks or corrosion and we have them drained and refilled plus corrosion inhibitor every 10 yrs or so.
That's the background.
Sometime in the next few years we will be selling and moving and will need to replace the boiler prior to this to encourage house sale.
One engineer told me that a new boiler would not fit well with the old ,long c/h system, amount of water circulating etc and that it would soon become contaminated by corrosion from the pipes/rads. Is this the case, would a new,( obviouslly a high capacity one with powerful pump) really be a dogs dinner ? If so we seem to be in a bit of a fix !

Any thoughts

Thanks
Brian

 

[JohnD]

If, as you say, it's very old, then the bit about having lots of sludge and corrosion inside it is going to be true

However:

If you have a Magnclean fitted on the return pipe to the boiler (the device will cost you £100 or so, you could do it yourself if you have copper pipes), and add a chemical cleaner to loosen the old sludge, then over a few weeks it will loosen a surprising and gratifying amount of the old sediment, which will be collected and stick to the magnet, which you can take out and clean from time to time.

Immediately before fitting a new boiler, the installer will want to give it another clean, in case any remaining sediment will clog up the new boiler, but hopefully by this time there will be much less remaining. Even a powerclean does not get all the muck out. And you will have had a more efficient system, less prone to blockage, in the meantime. The Magnaclean can be left in position and will catch black particles that might otherwise be pumped into the new boiler. There might be limescale deposits as well, but these will mostly be in the old boiler.

I am not a pro, but I did a similar thing in mother's 30-year old system during the summer, and got a lot of sediment out, it now seems very clean.

I don't know if there is any other cause for concern. lots of installers like to sell combis as they are relatively easy and quick to instal, but you are not obliged to have one.

 

[gas4you]

Its not so much the new boiler but the flushing that could cause a problem.

I always tell my customers that there is a slight chance of a leak in a radiator or pipe work do to the flushing cleaning out the system well.

As JohnD says, if it is properly flushed and cleansed then you should have no problem, a magnaclean wll only help matters afterwards.

If you are doing this to sell then the appearance of old style rads could also put potential buyers off.