Conventional to combi...

[amfisted]

I've noticed that "what would it cost to..." threads tend to nosedive very quickly, and I understand why. Regional variations, the deals available on boilers, the need to see a system and work out exactly what's involved before committing, even loosely...all fair enough. However, I'd appreciate a rough idea of what it would cost to replace a conventional open vented hot water and heating system in North Wales with a combi.

When we moved here last July we inherited this system, which to be fair is only five years old, but I find all those cylinders, tanks and things a bit scary. Prior to 2014 we had been blessed with combis for well over 20 years, and it was reassuring to know that there was nothing potentially horrible lurking in the loft, as well as having a system which, I thought, was much simpler for an DIYer to work on (apart from the boiler, obviously).

We currently have a Glowworm Flexicom 15x in a kitchen cupboard on the inner face of an outside wall, a hot water cylinder, pump, motorised valve and electrical control unit in an airing cupboard about 12 feet away on the same floor (its a bungalow) and all the assorted plastic tanks in the loft. I'm assuming that a combi would be larger and that it wouldn't fit in the kitchen cupboard where the current boiler is sited, so perhaps the cylinder could be removed (and weighed in) and the combi put in the airing cupboard. Gas and water services are easily accessible in the vicinity of that cupboard.

If someone could give me a rough price just to allow me to consider my options, I'd be grateful. Otherwise yes, I'll just do what normal people do, ring a few RGIs and get quotes. I'd prefer a WB or Vaillant, or even another Glowworm, but I'm open to suggestions of other makes with a decent name.

Cheers

 

[Dan Robinson]

Cost could be anything....


However, the key increases come from the gas meter being miles away from the boiler (likely to need upgrading).

Drains not near the boiler (unlikely in your case).

So expect 2 to 3 days labour plus materials


There are better boilers out there, but sack of notions of wb being decent just because you have heard of them.

 

[amfisted]

Thank you.

Drains are within a couple of feet of the wall outside the airing cupboard, and the gas pipe runs alongside the base of that same wall. I don't know how old the meter is but its outside, about four meters away from the above location as the crow flies.

I only mentioned WB because we've had two of them and they've been good, although the last one, a Greenstar 28i, did suffer a catastrophic leak just weeks after we had it fitted. Mind you, anything would have been good after an Ocean FF.

I'll get some local quotes.

Edit: which boilers would you say are better than WB?

 

[St0rmer66]

I think you're silly to replace it, personally. I'd have a cylinder in my house if it was practical, rather than a combi.

 

[Agile]

If you are in Bangor or Conway then you have a fair choice of installers and I think their prices are probably pretty average for the country. If in Betws-y-Coed then more travelling time might be involved or far less choice.

Its not good time of year to think of replacing boilers as we are starting to be busy with winter repairs. All servicing and replacement boilers should be done during quieter times during the summer.

I don't see any immediate need to replace the boiler now if all working. Nor would I ever recommend that you replace it with a combi either and particularly not if there are more than two people living there.

To replace with a new heat only reasonable boiler, I would usually charge about £1640 but to convert to a combi about £2200! TRVs and mag filters extra but includes cleaning.

Tony

 

[amfisted]

Thanks again. The question of combi versus conventional has probably only come to the fore because of the issues we've had with air, so in a week or two when the gurgling stops I'll probably start worrying about something else.

But your advice and suggestions are still most welcome.

I did look online at combi prices and to be frank I was astonished. We paid BG about 1500 quid ten years ago to fit a WB in the same position as our old boiler, and it looks like the boilers alone are around that price at this point in time.

 

[Agile]

Most better boilers are between £800 and £1200 to buy including the flue now.

Good value in my opinion compared with some other things people spend money on like Golf Club memberships at about the same prices in London.

Tony

 

[Dan Robinson]

Consider keeping the boiler, sealing the heating system, change the cylinder to unvented.

Best of both worlds if done correctly.

 

[amfisted]

Thanks again. As I'm sure contributors will be aware, my query was prompted more by an erosion of confidence in this system due to the "air entrainment" situation than any serious disadvantage that I've identified in comparison with a combi.

I suppose I could easily find a better use for the two or three grand that the change to a combi seems likely to cost.

What exactly would sealing the system and changing to an unvented cylinder involve, Dan?

 

[Agile]

I expect Dan will say fitting a PRV, an EXV, a filling loop and a couple of AAVs. Plus of course the UV cylinder itself and its controls.

Quite a bit of work for which I would be charging about £660 plus cost of cylinder. But it would give a better flow rate than a combi. Also it would have a back up electric heater in case of boiler failure.

Tony

 

[amfisted]

Thanks, Tony. You'd have to explain to me what some of those acronyms mean for me to have a fuller understanding.

I'm all too well aware of what an AAV is.

 

[Dan Robinson]

Expansion vessel, pressure release valve and filling loop.

An hour or two and job done.

Bigger the vessel the better.

 

[amfisted]

Thank you. I remember those things from when we had a combi. Ahhhhh...memories.

 

[amfisted]

Well, I gathered all my reserves of courage and opened up the Magnaclean. So far no leaks, though one of the valves did get a few more turns than necessary because I didn't have my glasses on and assumed it was "rotate until you can't rotate no more", rather than as it happens, a half or maybe quarter turn till "off" appears on the spindle. It was pretty mucky inside and I'm glad I went for broke.

It looks a fairly easy job to remove the Magnaclean completely, should I want to, and replace it with a straight section of pipe. The filter is installed on 22mm pipework, it's right smack on top of the boiler, which is inside a kitchen cupboard, and TBH I'd be worried about getting water into the boiler gubbins when I release the couplings.

Would there be any particular problems in doing a straight swap with a Magnabooster?

 

[Dan Robinson]

You'll never get a magnabooster in there.