LG John

Ok, this might take a bit of time to explain...

We recently moved into a new house that has a standard gas boiler in the utility room. It operates as a slave to a Boilermate 2000 which resides upstairs in a cupboard. The Boilermate stores 150-litres of water in it at a constant 60-degrees and will call upon the boiler downstairs to heat it's stored water back to 60-degrees when it drops below a certain level.

The 150+ litres of water is in a closed system between the boiler downstairs, the boilermate and, presumably, all the central heating radiators as well. Heat for taps and showers is created by running mains pressure cold water through a heat exchanger in the Boilermate.

This set up is amazing in the winter as your radiators are boiling within seconds of turning the heating on and you can hammer into the showers at the same time. Also, there is effectively underfloor heating upstairs because of the run of pipes between the two boilers.

However, in the summer it's a nightmare for two reasons: 1) Upstairs is roasting hot, always. 2) Our gas bill for 3 months was £188 and that's with the heating set almost permanently at 5-degrees (i.e. off) and cooking around 1 hot meal a day for two people.

We've found the solution is to turn the boiler downstairs on before going to bed and then off again in the morning. The hot water in the system lasts us all day and despite the boilermate asking for heat when it drops below 60 degrees the boiler is turned off and can't fire up. We believe this will make a significant saving in energy useage during the summer and, crucially, I don't lie tossing and turning at night as I'm too hot (granted it'll get hot but I'm asleep before the system is fully heated up).

Turning the boiler on and off seems to be the only solution. If we turn the boilermate off it's pumps go off as well meaning it won't flow the hot water through the heat exchanger meaning we don't get hot water.

soooooooo.......getting to my point.....

It's just a matter of time until we forget to turn the boiler back on before going to bed and wake up to cold showers. We therefore need a timing solution. The boiler seems to be connected to a fused switch, not unlike this one...



My question is this, could I use this product to replace the existing fused switch and would it be hard to wire up - I've done basic 1 and 2 gang plugs before. I'm guessing it's ok given that it's 13amp and can run appliances up to 3kW. The boiler is gas powered so can't draw much electricty surely? Also, I take it this product does what I expect....i.e. only supplies power to the wired in device at the times you program into it.

....is this my solution?

Cliff Notes

- Had brutal summer gas bill
- Want to use timer to control when there is power to the gas boiler
- Will linked product do the job and be safe?

ALi-B

iTrader: (1)

In short; yes that would be a quick fix for the problem.

However there is an issue that the Thermal store will call for heat and run the run pump that circulates water through the boiler whilst the boiler is turned off; this will cause heat loss from the tank as it is effectively turning the boiler into a radiator. Ideally this pump also need to be disabled, whilst allowing the one that serves the hot water to still operate as and when required.


Also I guess the pipes going between the thermal store aren't insulated properly either (seeing it heats your floor/upstairs. This serves as a double no no as when the system is switched off or in idle (no demand) you are losing heat from the tank as water circulates (albeit slowely) via thermal convection.

In an ideal world, those pipes need to be lagged to stop it heating your floor, and the unit retrofitted with a programmer that can be set to give you hot water when you want as well as when you want the heating to come on, or one with some form of summer economy mode. If such a thing exists.

LG John

Yeah the two issues you identified are unavoidable and the pipes are defo not insulated.

However, the heat loss is still slow enough that if all of that 150+ litres is sitting at 60-degrees when you turn the boiler off you have enough capacity to have two showers in the morning, use hot water during the day, and have a slightly tepid shower at night.

In my mind it would be better to have the boiler turned on from say 5am-7am to ensure the water is all fully heated up first thing in the morning. That 'charge' will last right the way through until about midnight that same day. The alternative is that the boiler is constantly being asked to top up the heat 24/7 at a cost of around £60 a month in gas during the summer months. Hoping that my approach might half that then, when winter comes, I'll adjust the timer program to ensure there is much more regular heating of the water (or possibly leave it on all the time).

Leslie

Looks as though it should sort the problem alright, and there are only three wires plus an extra earth on a ring main. As long as you understand the way the switch is wired in it should not be difficult to do.

Les

LG John

Cool, just been chatting to my father in law about it (who has more experience of such things) and he agree's that it should be relatively straightforward.

I take it there is no harm in water flowing through the gas boiler when it's turned off? I also take it there is no harm in having the boiler powered on and off completely once or twice a day?

Leslie

Can't think why water flowing through it should bother it. Its supposed to be watertight anyway. If there was a problem switching it on and off it should say so in the instructions for use, or you could check with the maker to be sure anyway.

Les

Devildog

Kenny,

Would you not be cheaper replacing the boilermate with somethng like an unvented cylinder fed from the boiler?

Or going the combi route?

As you say, all that heat in the summer is simply wasted energy and your costs prove the system is not efficient.

Must be some form of grant available?

Other alternative would be to run the boiler and the heat exchanger run pump on a timer switch so they come on at the same time?

Last thing to bear in mind - the energy required to heat up the heat store from cold to 60 degrees may well be greater than that required to keep topping it up at 60 degrees, so you might not be any better off financially.

LG John

We are renting at the moment which is why I need a relatively non-intrusive solution that I can quickly undo myself if need be. That is why I think changing the switch that controls the boiler to a timer is the best way to go. If it was my house I would certainly be considering an alternative set up.

That said, this set up will be amazing in the dead of winter....it's just overkill in the summer.

dunx

iTrader: (3)

Similar set-up here, but fed by a combi, and we have the timer set for 6AM till 7AM, and 8PM till 9PM.

Two showers in use.

dunx