Help me sort out our heating

(9 Posts)
FlightofFancy Wed 09-Oct-13 13:42:53

Sorry it's long - don't want to miss anything important.

We recently moved house and having issues with the heating. We’ve got a condensing boiler, controlled by a wireless room thermostat in the living room. There’s no separate timer for hot water. There’s an immersion (with a clock timer) but that’s only for extra – most of the hot water seems to come with the heating.

The theory seems to be good – the room thermostat can be set to different minimum temperatures for different times of day/days of the week and my understanding of how it should work is that if the temperature in the living room (central part of the house) drops below whatever the minimum we’ve set for that day/time is, the heating kicks in.

However, we can’t seem to get it to work like this. Initially we had nothing – so discovered the battery had gone flat in the wireless thermostat. Replaced that, then the boiler was heating up but going in to ‘lock out’ mode. Got a man in from the boiler care people in to fix that (blocked outlet pipe, all sorted). Boiler working as planned now, but seems to be on constantly. As the weather is warm, we’ve turned all the radiators down – most have thermostatic valves, but those don’t seem to work properly either.

If you turn a valve on the radiator to anything above 2, the radiator is roasting hot within minutes, whether the room thermostat is telling the heating to be on or off. The living room can be 25 degrees, with the room thermostat set to 17, and yet the heating still seems to be on.
We’ve been trying to get a heating engineer in to look at this for a couple of weeks, but it’s the usual issue getting hold of anyone.

What can we try?

specialsubject Wed 09-Oct-13 14:39:25

just a thought - thermostatic radiator valves don't last forever. In my experience after 8 years or so they need replacing, especially if previous owners didn't leave them open over the summer. This makes them stick and it is game over.

PigletJohn Wed 09-Oct-13 14:39:38

It sounds like you have a hot water cylinder, is that right? What colour is it?

If the CH is on when the programmable thermostat tells it to be off, then you probably have either a fault in the wireless sender or receiver, or in the 3-port valve. Get the instructions for your wireless stat and read them carefully in case you are on override. If you have not got them, you can probably download from the maker's website.

On the side of the HW cylinder will (should) be a thermsotat, that fires the boiler when it feels cold. Observe the small adjustment screw. Turn it down, you should hear it click and the boiler may stop firing.

Thermostatic radiator valves can go wrong, usually if old and/or a poor quality brand. What are yours? Turn them to a low setting, but not fully off, and wait 20 minutes. Only ever adjust them a tiny bit at a time. Don't turn them fully off or fully on.

FlightofFancy Wed 09-Oct-13 15:27:26

Thanks - will have a go at that. We've got an option for resetting the room thermostat box - putting the system in something called 'learn' mode, so will try that. I'd wondered if the boiler being switched off/battery going had reset the connection (am more familiar with IT stuff than plumbing).

Will have a look at radiator valves this evening (at work at the mo) - but presume would be unusual for all of them to go wrong?

PigletJohn Wed 09-Oct-13 15:40:09

also look for the "holiday" setting of the programmable stat. It enables you to set it at a continuous 12C or some such temp, for a number of days, as you might if you went away in winter. This (should) have the effect of putting the CH off unless weather gets a lot colder.

The boiler stat can be set to 60C, which is the most efficient and economical temp for a condensor. If the cylinder stat is set lower than the boiler stat, the boiler will never stop (unsuccessfully) trying to satisfy the cylinder.

FlightofFancy Wed 09-Oct-13 16:01:06

That's interesting on the cylinder temperature - we've got roasting hot water, so have been turning the temp gauge on the water cylinder down to try and make that slightly less lethal.

PigletJohn Wed 09-Oct-13 19:58:35

plumbers usually set the cylinder temp to 60C, which kills legionella in about 3 minutes, in the unlikely event that you have any in your copper cylinder. The trade associations keep reminding them of the possibility.

However at temperatures above 45C it will not grow and multiply, so there are people, such as me, who keep our own HW at 50C to 55C, which kills legionella in about 6 hours.

It is much more likely that bacteria will grow in warm water at around body temperature, for example an open tank, which has not been insulated, in a loft on a sunny summer day. This is the important reason for keeping loft tanks insulated, tanks themselves seldom freeze in winter. the incoming water from the main is also generally too cold for bacteria to grow. A tight fitting lid will prevent dust, dirt or spiders falling in.

If your HW is scaldingly hot, it is likely that the thermostat, if correctly set, is faulty or possibly (if it is the sort strapped to the side of the cylinder) has fallen off or is not in contact with the copper.

PigletJohn Wed 09-Oct-13 20:01:58

plumbers usually set the cylinder temp to 60C, which kills legionella in about 3 minutes, in the unlikely event that you have any in your copper cylinder. The trade associations keep reminding them of the possibility.

However at temperatures above 45C it will not grow and multiply, so there are people, such as me, who keep our own HW at 50C to 55C, which kills legionella in about 6 hours.

It is much more likely that bacteria will grow in warm water at around body temperature, for example an open tank, which has not been insulated, in a loft on a sunny summer day. This is the important reason for keeping loft tanks insulated, tanks themselves seldom freeze in winter. the incoming water from the main is also generally too cold for bacteria to grow. A tight fitting lid will prevent dust, dirt or spiders falling in.

If your HW is scaldingly hot, it is likely that the thermostat, if correctly set, is faulty or possibly (if it is the sort strapped to the side of the cylinder) has fallen off or is not in contact with the copper.

PigletJohn Wed 09-Oct-13 20:33:06

ffs

bloody beaker people slowing the site to a crawl

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