Gas Boiler - who to trust and what is best?

bundly

Southcoastrgi can I ask you a couple of other things?

I have a three storey Victorian house with ten radiators. Even with all of them on at 30degs the house is never really warm I suppose because of the high stairwell, high ceilings and the fact that all the doors and windows are original and have gaps and so there are lots of draughts rushing around the house.

My RGI suggests a 24kw boiler (The Vaillant) but this means changing a section of pipe which is only 15mm, to 22mm. I would rather avoid this, as the pipe runs down behind fitted kitchen units and I honestly cannot bear the thought of all the mess and disruption of him ripping half the kitchen out to replace the pipe. Apparently if I have a 18kw boiler we won't have to replace the pipe.

Question (1) is, would an 18kw boiler be OK in such a house?

and (2) is, would it help if I changed all the single-panel, 25-yr-old radiators to double ones or super-charged ones (if such a thing exists).

I'm asking you rather than the guy I am with cos he has a financial interest in this and I'd prefer to get the opinion of someone completely unbiased.

B.

southcoastrgi

If your rads don't have fins on the back then they are called single or double panel rads, modern rads are called convector rads because they have the fins, for the same heat output a convector rad will be about half the size of an old panel rad,

Modern rads now give out the same heat for a lower DT (delta T), this means the output quoted for the rad will be achieved by a flow temp of 50d so you could run the boiler at 60d (which is what your hot water will req anyway),

The gas supply for any boiler reqs the correct vol of gas, you can't automatically say this boiler reqs this size pipe & another a smaller or bigger pipe, it all depends how far the boiler is away from the meter & how many bends & whether anything else is connected to this pipe, you aren't allowed on a new/replacement install to have any more than 1mb difference working pressure between the meter outlet & the boiler inlet with all gas appliances working, so it maybe the case that a 24kw will req a 22mm gas supply & may even need upgrading to larger than that off of the meter for a certain distance but equally a 18kw might need the same,

Rad sizes are based on an outside temp of -1 & working 24/7, most installers will oversize the rads slightly in case the temp drops more than that & that no has the heating on 24/7, you have answered your own question will regard to draughts around the house,

They are rad calculaters free to use on the web that you can put your room sizes into, this will then give you the heat output for that room, do them all & add them up, add 2000 btu's/0.6 kW then add 10% & that is the boiler output size you need

bundly

southcoastrgi wrote: »

If your rads ...size you need

Many thanks for this info, SCRGI.

It's all a lot more complicated than one might think.

I guess I am just going to have to place my trust in my RGI.

B.

rgannon4

I was reading a article in the telegraph about there being no need to get a new boiler and that spare parts can extend the life...?

http://www.telegraph.co.uk/finance/property/11395273/Jeff-Howell-spare-parts-can-extend-the-life-of-your-boiler.html

bundly

Thanks for that Rgannon.

We had another incident of banging and rattling today, followed by water pouring from the bathroom ceiling.

I fear that the cost of repairing the boiler, new circuit board, new thermostat, power flush, magna flush, etc etc will end up costing me nearly as much as a new boiler, and at the end I will still have a G-rated old boiler that could go wrong again and again ....

southcoastrgi

& I still don't think it's a boiler problem

bundly

southcoastrgi wrote: »

& I still don't think it's a boiler problem

Yes, you said that "the first thing I would look at is the central heating pump is working & to make sure the roof tank (smaller one) has water in it & the ball valve isn't stuck up & that the cold feed from it isn't blocked".

My RGI has spent a lot of time here, investigating everything. Surely he must have checked all this? He hasn't told me what he's looked at and what he hasn't looked at. He just said I need a new boiler without discussing with me why he came to that conclusion.

Last week he appeared with a coil of wire of some kind in a sealed packet and fitted it to the boiler that took about an hour then he said it was an experiment to see if that would stop the boiler overheating but we still got a load of water pouring through the ceiling.

He has ordered a Vaillant EcoTec Plus 418 and is coming on Monday to perform the power plush and remove my old boiler.

Bundly.

southcoastrgi

It sounds to me that the boiler is making a noise because the heat can't get away from it, so unless the boiler stat & over heat stat has failed this isn't a boiler problem, not being funny but how old is this guy ? He may not be used to old school open vented systems & their pitfalls

bundly

southcoastrgi wrote: »

It sounds to me that the boiler is making a noise because the heat can't get away from it, so unless the boiler stat & over heat stat has failed this isn't a boiler problem, not being funny but how old is this guy ? He may not be used to old school open vented systems & their pitfalls

He looks about 40, but he's foreign, so maybe not been working on British boilers for very long.

The English guys who also looked at it were a bit younger. They also said I don't need a new boiler, just a flush, which they quoted 720 pounds for.

What do you think is wrong with it?

I don't have a deep understanding of CH.

He's ordered the boiler and all the parts. I guess I only have another 24 hours to decide what to do, as I am going to pay for it all 0700 tomorrow.

What my RGI said was, we could try doing this and that and the other to the boiler in the hope that one of those things fixes it... for example, change th thermostats, then change the circuit board, do the flush... but each of these procedures will cost a few hundred quid, totalling, say, a thousand pounds or more, and at the end of it all I'll still have a 25 year old inefficient, G rated old boiler which could go wrong again at any moment.

He thought it was more economical in the long run to replace the boiler.

And the other guys giving me a quote of 720 just for a flush proved that these procedures are pricey.

None of the other ten or more RGIs that I phoned to get a third quote ever returned my calls, texts or emails. That makes me feel lucky to have this guy AT ALL,, to be honest. He always answers his mobile, even on a Sunday.

I feel torn between going ahead and calling it all off and insisting he start with the repair experiments.

southcoastrgi

if it's getting too hot then it could be the boiler stat, it is very unlikely it's the pcb, a powerflush might sort it or the other things I said in #4, the trouble is that he is going to flush it & then fit the new boiler (you don't want it flushed after the new boiler because you will be putting any crap in your system into the new boiler), so you won't know which has solved the problem & you have paid for a new boiler you might not need, I don't know the area of the country you are in but around here you would be looking between £300-£400 for a powerflush