Confused about heating/ immersion and everything else...

Falling

Heya,

This is probably a really silly question but we bought and moved into a 50 year old house late last year and I'm really confused about the hot water/ heating side of things.

The (oil) heating control is in the kitchen, which also heats up water. Grand. However there's no temperature control/thermostat on it, which seems weird to me.

In the summer we started using the immersion to heat the water as we didn't have the heating on and it was beyond useless. Luke warm water for a a few minutes after the immersion being on for a while (and costing a bleedin' fortune. I finally understand what my parents were always giving out about...).

Maybe it's just a really crap old immersion, although the tank and everything looks relatively new.

Is there a way to heat the water without having the heat blasting or using the immersion?

This is such a newbie question. How embarrassing.

CoBo55

Can you turn off the radiators individually or are the taps too corroded? Most likely the only temperature control on the system is the thermostat on the boiler.

Falling

Could probably turn a few of them off. Must have a look at them. I had to get the screwdrivers, clamps and pliers out a while back but might manage it.

I'll go and have a look at the boiler too and see if I can find the thermostat.

Does that mean if all the radiators were off, I could turn on the heating and it'd just heat the water then?

Cheers.

Tails142

The immersion should have the water pretty hot after about 40 minutes. You may want to use the bath setting which heats the whole tank, the sink setting if you have it just heats the water at the top, the thermostat turns off power once water is at temp so if you have a well insulated tank it really doesn't use that much power, but maybe your tank isn't well insulated if it just has a loose lagging jacket.

Thermostats can go faulty or previous owner may have adjusted the target temperature down to save energy so that is something to look at.

The problem can be if you're washing dishes and turning the tap on and off you get a thing called cold water sandwich where the hot water from the tank is being drawn down through long runs of pipe with no insulation so by the time it reaches the tap downstairs it has cooled, especially if you're starting and stopping. If you run the tap constantly for a couple of minutes after the tank has had time to heat and you still don't get hot water it is likely not this causing the problem though.

It's not a common thing to do but we have no bath in the house just an electric shower, so I took out the hot water tank and put in two ariston hot water heaters under the sinks in the kitchen and bathroom, I find it great because the hot water comes instantly and have no regrets but heating your water from the central heating boiler is the most efficient way to do it. Modern heating systems have valves so the boiler can fire up and just heat the hot water tank on its own and there is no wasted energy heating radiators unnecessarily.

My mantra is that the biggest energy saver is just not heating water at all though so the hot water heaters I have are on timers and it just comes on for a short time morning and evening for the bathroom and a couple of times during the day in the kitchen, they are small well insulated units so the water stays hot inbetween for hand washing etc. We plan to renovate in the next few years though so I will probably go back to having a tank as we will be adding ensuite toilets and extra showers but it is a good solution if you're not satisfied with your current setup.

One of my friends was going for a passive house build with no heating system other than air heat recovery and he put them in too so they must be on the economical side of things. Just remember hot water going down the drain is basically money down the drain.

Falling

Cheers for that- it's really helpful.

We'll be getting a dishwasher soon. I just couldn't look at the amount of water being wasted and the amount of energy being used up for very little return. And the dishes were still greasy half the time as the water just wasn't hot enough.

We don't have a bath either so your move sounds interesting. Do you mind me asking if they were expensive and/or difficult to install?

Our tank is pretty well insulated- it's got the newer, harder insulation around it so maybe I should just be putting it on bath and switching it on.

Wearb

It's not uncommon for old heating systems to be fitted without a thermostat and allow the boiler stat to control the heating. Not efficient at all.

It would not be a major problem to retro fit a room stat, in most cases.

Secondly I would invistigate the possibility of having hot water, living area seperated from bedrooms by zone valves. You will need a plumber out to advise on this. A lot will make a big deal out of doing it if the re piping is difficult, but try an get a quote for doing that.

It shouldnt be too big of a job to seperate the heating from the hotwater with a zone valve if the above is very onerous.

Falling

Thanks for that.

Does that essentially make it more efficient in that you can switch it on where it's needed and funnels the heat that direction?

Must ask the plumber about getting a thermostat alright. I'd meant to and forgot when he was round the other day. Typical.

CoBo55

https://www.boards.ie/discussion/comment/117894200#Comment_117894200

Get some 3 in 1 oil and take the plastic cap off the tap and put one or two small drops on the centre shaft, you only need to close one tap on each radiator to stop the flow. Be gentle with them initially when trying to turn the spindle and use a small vice grips or pliers on the flats, don't use the plastic cap as it will round off. You don't need to be king Kong tightening them closed just enough to stop the flow of water. Maybe consider getting thermostatic valves as they're much easier to open and close.

cruizer101

30 min on immersion on sink should be enough for a reasonable enough shower maybe a bit longer but if it is on over an hour and still not enough for a shower it sounds like something is definitely amiss.

Heating from the boiler is more efficient but depending on the piping could be tricky to zone it separate.

Maybe put up some pictures might help in advising.

CaptainCoPilot

Theres a couple of options available to you depending on budget etc.

Firstly, an immersion heater should generally be considered a "back-up" means of heating the water. It is more efficient to use your oil to heat the water.

Option A: The most basic option is to ask the plumber to put a manual valve in the hotpress that when turned one direction the boiler only heats the hot water and the other way it heats both hot water and the radiators. This is often called a Summer Valve.

Option B: The next option is to put a motorised valve to do the same as the above, except instead of having to go in to your hotpress and manually move a valve, you can put an electric switch next to your heating controller to choose between hot water and heating + hot water. This will be a bit more expensive than Option A, but far more convenient.

Option C: Move to a thermostatically controlled zoned system. Impossible to give you an estimate here as it really is a function of your system layout and how much pipework needs to be changed, where thermostats can be located etc. It is a more significant investment but is the best way. Your heating/hot water will turn off once the desired temperature is reached and you can integrate google nest etc so can control remotely.

TLDR, get advise from a customer but Option A and Option B are two low cost options that will work on your system and increase your efficiency a lot.

Vikings

https://www.boards.ie/discussion/comment/117894537#Comment_117894537

Just to add for Option A you can also get a smart (WiFi) switch to do this. We have this summer valve in our hot press to turn off the hot water going to the radiators, I'm about to replace it with a smart switch so stop the trips to the hot press all winter when the house gets too warm but hot water is still needed.

Going a little deeper on this I've a Tado heating controller and wireless room stat. My set up will all utilise an app called IFTTT (if this, then that) which will give me an automatic control over the heating and water based on readings from the wireless room stat. I can set the heat to come on if temperature goes below X, turn off if it goes over Y etc. I will have hot water at all times the boiler is firing but can have it set up to control the smart switch to stop heating the rads depending on readings from the stat.

POBox19

If the immersion is not heating the water in the tank sufficiently it could be that the internal thermostat is set too low. You can remove the cap on the immersion and you'll see the thermostat inside and just turn it up a few degrees, it may never have been set from new. If it is getting hot but goes cold quickly check for leaks and also check that the non-return valve to the boiler is not open allowing all your hot water to run back down.