Heating question.

[Lanzecki]

I think I've the right section. If not, sorry.

I'll try and keep this short and succinct, but I tend to ramble.
I recently had some building work done that included a new boiler and some new radiators, a new stainless hot water tank (hard water) and associated pipe work.

Allow me to describe my system as an open vented system with a new oil fired outside boiler. This supplies hot water to the heating system and the hot water tank at the same time constantly. While there is a time clock we don't tend to use it, but just turn the boiler on and off as needed. The current system is a modification of what was there before that was installed in the 80's and while it works, it's not efficient or modern.

The current method of controlling the boiler means we either freeze or boil until we remember to manually turn it on or off.

All the radiators (except 2-3) are now linked in parallel instead of the previous series linked system, but as one ring or zone if that's the right word.

Since the new boiler's gone in (and is soooooo much better then the old boiler) we have an in-balance in the heat generated in some rooms, for instance 2 of the bedrooms boil before the living spaces are comfortably warm. I'm thinking that a bunch of thermostatic radiator valves are the answer here? These 2 rads were installed 8 years ago and are overly large for the rooms now, but were needed at the time.

The living room thermostat is not used (not wired in). And there are no automatic valves to stop hot water flowing around the rad's when not required such as the summer when we might want just hot water.

I have the know-how and ability to drain the system and fit the thermostatic valves to the rads, and do most things to the system. But I don't know much about the correct way to wire in the living room thermostat and fit some motorised valves to allow for just heating the Hot water or heating the rads as well.

This is where my know-how fails me, and I look towards hopefully more knowledgeable people.

Maybe a picture of how it's wired in may help: Scuse the picture I'm on my laptop.

​

If I fit a motorised valve to the location A, and wire that into the thermostat and a manual switch for just hot water or Heating and hot water will that work? Or should I have a motorised valve at B as well to totally cut off the rad's from the hot water.

The bolier does have a thermostat built into it, and that does cut in and out.

I assume that the time switch is correctly wired in as this cuts power to the boiler.

Hope that's clear.

I'm wary of the room thermostat as using that will, I presume, affect the other rooms. Maybe if I use Thermostatic valves I shouldn't use the room thermostat?

The time clock is the most basic of mechanical valves. I assume that I can fit a modern clock that would have the ability to control the boiler and the hot water / rad selection at the same time? When I lived in the UK, our heating system was digital and you could set the clock to come on later on the weekends and for longer etc.

I maybe thinking to old fashioned though? How do modren systems work? For all I know boilers stay on 24/7 and there are automatic valves all over the place with the timeclock controlling the valves.

All advice and smart comments are welcome.

 

[Over The Hill]

I have an oil fired system that is 20 years old and we put in a new boiler and upgraded it a couple of years ago.

New thermostatic valves were fitted to all rads (required now in regs in UK) but if you do this you also need to put in a shortcut between the in and out with a pressure valve on it so the water still pumps round a bit if the valves all shut down.
This just about makes the roomstat obsolete.
The controller is really just a complicated on/off switch and you can get a better one to fit quite easily.

The system then works by calling for heat, then when the rads are happy they shut down, water runs hot in the boiler and it shuts down.

Re the valves - One pipe from boiler with hot in should split at a "three port valve" This is a T shape valve with the "In" at the bottom and two "out" ports - one to rads, ohter to water tank. Controls set the paddle inside to be feeding just water, just rads or both.

Ours is set for two heating sessions - first thing and evening when it heats both house and water. we just flick the heating on if we need a boost if we are at home in the day.
I dont run it to heat just hot water in the summer but prefer to use the electric emersion heater then.

Hope that helps

 

[Lanzecki]

Guys,

Thanks loads for this. I didn't know about the 3 way valve, that makes a lot of sense. Everything said here was of use, and answered a lot of questions. I'll have to drain the entire system so I want to get everything ready to do this all at the same time.

Apart from thermo valves I want to fit some gate valves so as to be able to shutoff part of the system for servicing etc. The heating system as a manifold supplying the rads so a few valves there while I'm fitting the motorised valves and thermo valves.

There is no way of disconnecting part of the system from another, so if I have problems in the future I'd have to drain the whole system.

Thanks again, things are much clearer in my head.

 

[Andy_R]

IIRC, the room thermostat controls a pump which circulates hot water through the radiators. The way it works is simple: boiler fires and heats water. Hot water goes to a cyclinder (airing cupboard). Hot water for heating is circulated by pump through a heat exchanger to heat radiators. Hot water for taps is direct from cyclinder that is topped up with cold water, heated, and released to hot water taps)

 

[derrick]

Can't you just close the bedroom valve down a bit,

 

[Lanzecki]

IIRC, the room thermostat controls a pump which circulates hot water through the radiators. The way it works is simple: boiler fires and heats water. Hot water goes to a cyclinder (airing cupboard). Hot water for heating is circulated by pump through a heat exchanger to heat radiators. Hot water for taps is direct from cylinder that is topped up with cold water, heated, and released to hot water taps)

I cannot comment, but when I turn on the boiler on my system the pump starts and stays running as long as the boiler is powered. This hot water enters the house and is free to flow in to the hot water coil and the radiators at the same time (Via a t-junction). There is no control over how this water is directed. This is what I want to do. Amongst other things.

What I'm planning to do is install a controller and powered valve that will direct hot water to either the rads, the H/W tank, or both as needed by the controller (Thermostats as well). I've been told I need a H/W cylinder Thermostat that along with the controller will stop the flow of heated water once the H/W tank is hot.

Fitting TCV's (Thermostatic valves) to most of the rads (All except the bathrooms) will mean that the rads are temp controlled. I.e. they will stop the water flow once the room is at a pre-set temp.

For the sake of argument, once the house is at the right temps, The boiler will only be supplying water to the loop to the bathroom rad (no TCV remember) this water will eventually hot the boilers pre-set max temp and the built in thermostat will stop the boiler, but the pump keeps pumping water around the bathroom > boiler loop. Once a few rooms cool down the TCV's open to request hot water, meaning that cooler water from the rad enters the system again (the rad rejoins the heating circuit) and the boiler thermostat senses this drop in water temp and fires up again.

It sounds complicated, but a 2 channel controller, a 3-way Mid position valve, a room and H/W cylinder and some TCV's and I'm good to go. And I understand it's they way modern houses are done.

I only have one heating circuit. Since I have no up-stairs. Ideally I'd separate the bedrooms from the living area's but short of re-piping that's not going to happen.

This system was similar to the house I owned in the UK (10 years ago), and was very efficient and cheap to run. With the rising cost of kerosene and after buying a new boiler I've realised that my current 'open' system is not very efficient. The old boiler would have to be run for 2-3 hours for the house to be overly warm. Since the new boiler it's 30 mins.

The plumber that installed the boiler wanted another €600 to do the job. Parts from local suppliers will cost me around €150, and I not feel confidant that I understand what needs to be done enough to do it myself. The most awkward part is to drain down the system. Something I only want to do once. Filling it's a git as we have 'solids' in our water, not to mention it's very hard water. Enough said about that the better

Can't you just close the bedroom valve down a bit,

If just slow the radiator down a bit. I.E. it still heats the room to very hot temps (the room used to have very poor insulation, and so the rad was over specced.

 

[goody]

Whether you fit thermostatic valves or not you first need to balance the rads so they warm up at the same time google it. you can do it reasonably well just feeling each rad by hand.

 

[rusty bearing]

Goody has given the right answer, balance the rads.
How?
Your rads have two valves on them, lets say one is the control where you might find a thermostatic valve, the other (most times)has a cap which just pulls of, used to be called a lockshield valve.
Open both valves wide on all rads, fire up heating system and let it get working. If you go round the rads you will find some way hotter than others. This is because the pumped water likes to take the easiest path. On those rads close the lockshield down until the rad is not so hot and the water is forced through the cooler rads. Takes a bit of patience but you'll get there in the end.

The wiring system you're talking about is 'y'plan if I remember. Long time since I've done one.
http://wiki.diyfaq.org.uk/images/thumb/1/11/Y-Plan-Wiring.gif/512px-Y-Plan-Wiring.gif

 

[Lanzecki]

Thanks Rusty. I found a wiring diagram from Honeywel for the Y-plan. Everything makes sense so far.

I googles ballancing rads and get the idea. And there was me just thinking the other valve was just for servicing the rad :0

 

[rusty bearing]

Glad to help.

 

[mickle]

Your system has not been installed in accordance with the regulations. Why arent you complaining to the muppets who installed it?

 

[Lanzecki]

We had some building work done including electrics and plumbing. Even in these days the contingency fund was eaten into and more.

An extra €2k for the builder for what I recon was his tea fund.

€2.5k for the sparky (justified),

The plumber got kicked off site after installing the boiler, and when asked for the required government installation cert he confessed that he wasn't registered to install boilers. I payed him for the kit only. And for the pipework and rads etc. He wanted an extra €750 fit the kit that I'm talking about. I can buy the same from a local plumbers merchants for €200.

That said the over run was expected. but the heating cowboy was the only problem we had.

 

[Davidc]

The system you have doesn't meet the current standards.

What's been said above about thermostats and 3 way valves is correct. Flow balancing using fixed valves will help, thermostatic valves will do the same job but dynamically, with faster warm up times. A thermostat as described by User9609 will save more and increase comfort, unless its a small house then another valve to set up zones for the daytime and bedroom accommodation, with timing and temperature control separated for them is another way to save money.

There are web sites from government, trade bodies and manufacturers with loads of good information on them.

It's amazing how much fuel is saved when efficient controls are added.