[Closed] Plumbererists! I need your help (boilers)

That sounds a little odd, are you sure you've more than just the one pump? They're usually very easy to replace and will have isolating valves so you shouldn't need to drain down the loop. Worst case would be what happened to me, I could undo the valves from the pipework but they were pretty seized on to the pump so I ended up just draining the system and replacing the lot. It still came in at well under £100. You'll have to be OK with wielding big spanners (or similar) and making electrical connections but it's all pretty straightforward.

Having said all that, AFAIK combi boilers have integral CH pump so if you go that route your fitter will presumably be removing your noisy old pump along with your HW tank as part of the install.

Combi will be simpler. No need for any extra pumps. Hot water on demand 24/7. For a small property they are the best solution IMO and worth the extra

@johnners

Well, there’s one horrendously noisy pump that comes on when the heating is on and another unknown humming that’s on when the hot water is “on” but not actually being heated, if that makes sense?

I’m not sure I trust myself with spanners...

I’m tempted to pay the £350 and get a Combi.

How much does a scrap yard give you for a hot water tank?! 🙂

Copper cylinder? Should be around £50, if the plumber doesn't take it away for you

I’m not sure I trust myself with spanners…

I’m tempted to pay the £350 and get a Combi.

It's really easy stuff but if you haven't got the tools or the inclination to have a go then go combi - you'll fix the pump issue without having to buy a new one or pay a plumber for that bit of the work. Plus maybe recoup something for the tank. Net cost will be a fair chunk less than the £350 conventional/combi difference.

The combi may well pay for itself versus a system boiler (non-combi) due to reduced losses of the water storage tank. Further you’ve got the peace of mind that all the moving parts of your hw/ch heating are in one brand new, guaranteed box.
Oh and your small house gains an extra cupboard!

Could just be pipes knocking rather than a pump?

Out of interest, why are you changing the old boiler - is it broken?

Out of interest, why are you changing the old boiler – is it broken?

Well, it’s about 30 yrs old and seems as efficient as a very inefficient thing - our gas bill is about £85 a month on average and we hardly have the heating on!

I have the opportunity for a free/ heavily subsidised new one so it makes sense.

Could just be pipes knocking rather than a pump?

It sounds whirry and pump like?!

The only thing I would say is that the owner of a long-standing heating engineers told me that, until the water jacket on my 30+ year old boiler cracked, I should not replace it as modern boilers are more efficient but certainly not designed to last - in fact they probably have obsolescence built in!

That said, ours is an oil boiler that's simple to work on - gas may be different.

Have you done all you can regarding insulation?

RRR, are you also known as Dan?

Insulation - loft has been done and walls are being “improved” hopefully next week.

I’m not actually *too* worried about the longevity of a new boiler as plan to move within 4 years.

old nick - maybe maybe. Maybe you’re Nicklouse eh? Hmmm? 🤔

I think the estimate of a hot water tank energy loss is 100w per hour. So 0.1 kWh. Gas 3p per kWh. 3*24*0.1 = 73 p per day

7.2 ppd sorry

Depends on the type of tank.
I constantly monitor the temps in a house we have that has a 210L Megaflo unvented system - in a 24hr period the tank loses 17c if left with no input which would take about 4KWh of power to replace (according to the formula I found).
So roughly 24p/day in reality - most of the heat in our system is lost not from the tank itself but from the hot water outlet on top.

Although I'm not a fan, in this situation (small house with 1 bathroom) I'd say defo combi.

£350 is likely for cutting out all the extra bits and replacing with copper pipe rather than extra cost of the Combi. For a small 3-bed with 1 bathroom I'd be very tempted to suck up the £350 and go with the Combi, plus then everything that could go wrong (other than pipe leaks) is covered by the boiler warranty.

Swings and roundabouts spring to mind. Combi might cause problems if you have a power shower (but it's another pump gone), and you'll lose your heated airing cupboard, but gain a pile of space. Immersion heater will also be a thing of the past. Get the largest output for your water supply flow / volume

and you’ll lose your heated airing cupboard, but gain a pile of space.

Put a small Radiator in the cupboard. Lots more space. and still an airing cupboard. 👍

We fitted an electric towel rad, a CH rad doesn't do much for 4 months

We fitted an electric towel rad, a CH rad doesn’t do much for 4 months

We installed heating elements into our CH towel rail so in the summer months we can electrically heat it, but in the cooler months the CH does it. The elements can be retrofitted to existing towel rails. Gas is 3.5 times cheaper than electricity so get the benefit of the cheaper heating during the colder months.

I constantly monitor the temps in a house we have that has a 210L Megaflo unvented system – in a 24hr period the tank loses 17c if left with no inpu

And no hot water draw off? Quite surprised at that. I am quite disappointed with how poorly some tanks and pipework is insulated.

Thanks everyone.

The hot water tank is in The Cupboard Of Doom, hidden behind a door hidden behind a desk. We tend to open the door a tiny bit, throw stuff in and run away (we have no idea what lurks within).

Sounds like it might be worth it and presumably I’ll gain a bit of loft space with the cold water tanks gone?

I just need to make sure the plumbers don’t “helpfully” take away all the copper for me..

I just need to make sure the plumbers don’t “helpfully” take away all the copper for me..

Good luck on that. It all goes in a bin back at the yard to be cashed in at the scrappy in December to pay for the Christmas do.