OLD TWIN PUMP HEATING SYSTEM REPLACEMENT

[Thomarse]

Hi,

Excuse my lack of techi knowlege on this subject, I will explain it as best I can! You may have seen me post on here before regarding my broken old Mechanical timer control unit for my CH/Hotwater system.

British Gas have told me that I can replace my broken Mechanical (Made by SMS) controller with a new digital one without replacing my twin pumps for one single pump/diverter modern set up. Apparantly this is because the system currently works on a series of relay switches which will not work if they put in a digital control unit.

As a stop gap to get me through they have wired me up a digital timer direct into the old control unit box and disabled the mechanical timer, however the only way I can switch between hot water and heating is to use the room thermostat as the relay switch in the old controller unit which does this is blown and is now no longer made/stocked.

For now I can live with this, but it seems that I will have to invest in a new diverter valve sometime in the near future, to bring my system up to date and also because the wiring they have left me with in my kitchen is extremely unsightly (insulating tape heaven!)

Does anybody in there experience have any idea how much it would cost to get my 2 twin pumps replaced with a modern diverter valve and new control unit, with labour included... British Gas have given me a quote with a discount of around =A3360 and I am unsure whether this is reasonable?!

Also, has anyone ever heard of such a problem before, as most posts on here make replacing an old mechanical control unit seem so simple!

Thanks for your help!

Tom

[Dave Plowman (News)]

Think BG are taking the p**s as usual. If you go to this site:-

download the Replacement Guide for an SMC system you'll find the only extra component needed is a changeover relay - you retain the twin pumps and don't need a three port valve.

Suitable relays might be difficult to come by on a single basis as most electronic suppliers have a minimum charge, and might need the sort of connections an electrician isn't familiar with.

One way would be to buy an octal plug in type which with matching base which gives screw connections. They have actually two sets of changeover contacts but you only need to use the one set.

See:-

508 for the relay, SR 511 for the base.

All it needs is an electrician with a couple of brain cells to fit the lot.

[Thomarse]

Thanks for the reply Dave,

I had a look at the links you posted and they are certainly very useful, it proves what I thought would be the case all along. I will be getting on to British gas and pointing them in the direction of these parts and asking them to explain why they cant do this? I have a service cover with them, so they should do this for me.. Its an on going saga which I have reported to Trading Standards.

On a side note however, would you say that it would be more efficient to have a three port valve? I am just thinking in the longer term when I come to sell the house whether getting this work done at some point would be worth it?

For now though I just want a working control unit in my kitchen that doesnt look like its been fixed by my 18 moth old and taped up with sticky tape!

I will get > > > Does anybody in there experience have any idea how much it would cost

[Andy Hall]

The next quote will be for a new boiler at £4k..... :-)

Grundfos has a twin pump unit. UPP 15-50. This comes complete with wiring controls etc. such that it can drop directly into a heating system with standard programmer, thermostat etc.

However....... list price is £155.

could be a bit less

a 3port valve and standard pump would be less expensive in component cost but may need a bit more plumbing reworking.

I don't think that it factors into ability to sell the house because most people have little idea about CH components.

[Dave Plowman (News)]

The answer might be is it's not in their colouring by numbers book...

Good luck. My brother is having much the same problem. Totally incompetent 'engineers'.

I'm really not sure. My self installed 30 year old system uses a three port valve. They are, of course, about half the price of a pump. My worry with two pumps would be the central heating one sticking through not being used in the summer months. But then three port valves ain't 100% reliable.

Off the top of my head, you should have all the wiring needed already in place between the programmer and pumps, so fitting the new programmer and relay shouldn't be that involved. But electricians can be funny with something they've not done before...

You're unlikely to get through to anyone who knows what you're talking about. Sadly.

[Thomarse]

It seems to be a common problem with British Gas.. It took me weeks just to get them to phone me back about the problem, and even then after dozens of promised phone backs etc it took a very stern letter to prompt some action.

3 engineers later, 1 which couldnt work out what to do, who came back a week later and then still couldnt work out what to do, then another who came after that who wiered in this temporary digtal timer onto my old unit, didnt have any rawl plugs of his own so borrowed mine, didnt have a cable deterctor so guessed where the wires might be in the wall before drilling and then left me with a taped up box on the wall... PLUS the new timer he added on didnt do anything as he had wired it up wrong. Then the 3rd one who fixed that problem and told me that I needed to ugrade this and that and basically that I needed a new system...

I have the mobile number of teh service manager now and he rang me yesterday to apologise (only because my MP had written to him to complain). And now I find out that they are telling me rubbish about having to replace my twin pumped system just to get a ne control unit.

It is crazy that they cant jsut sort this problem out for me. But then again they do just want to sell new systems!

If I ever get this sorted by them I will post it > > > I had a look at the links you posted and they are certainly very

[Guy King]

The message from "Thomarse" contains these words:

How do you think they're able to afford all those expensive vans and telly adverts?

[Doctor Drivel]

My God, not again!! Good quality 3-Ports valves are more expensive than a pump. Pumps are far more reliable and don't have mojor restrictions in the pipework that 3-port valves give.

[Thomarse]

[Guy King]

The message from "Thomarse" contains these words:

Probably their "engineer" can't understand anything different.

[Doctor Drivel]

Yes.

[Andy Hall]

Because that's what they have on the shelf....