I have an unbalanced heating system in this 2 bed bungalow. I have a quote to help me sort it which consist of putting a new 2 metre (appx) radiator in the lounge with thermostatic valves, replacing the lockshield on the 9 other rads with thermostatic valves and replacing the copper cylinder with an insulated one.
I have been told it's 3-4 days and been quoted £1,375 plus VAT (£1,650).
I am too old and creaky to do stuff like this myself any more, does that seem a reasonable price do you think?
10 off TVRs+lockshield = £120 to £250 depending on brand. 1 off radiator = £150 (depends on heat output/type) 1 off tank = £200 Replacement pipe work = ?
Say, £550 for materials + markup. (including VAT) That leaves around £1000 for maybe 25 hours of labour (£40/hour incl vat)
Many thanks alan_m :-)
Looks like it's about right then.
I have found a cheap IR thermometer good for setting the lockshields by checking return temperatures and adjusting accordingly.
IME you need to take a reading from the painted surface of the rad near the tail, or stick some tape on the pipe itself and read from that. (an unpainted metal pipe itself will have the wrong emissivity and confuse the thermometer)
I've found the bottom of a painted radiator to be pretty good at indicating temperature. But yes, some knowledge of IR emissivity helps.
YMMV
Doesn't sound unreasonable. Does the price include balancing? Installing TRVs doesn't remove the need for balancing if you want the house to warm up more or less evenly.
Are you sufficiently uncreaky to do that part yourself?
Thanks Roger :-)
I can set the TRVs and then use my couple of max-min thermometers to get temperatures about right. Not very scientific bit it'll do the job!
The balancing is performed with all the TRV fully open and the water flow through the radiators adjusted with the lock shield valves. Water always takes the easiest path and if you don't throttle the flow, say, to a radiator nearest to the pump a distant radiator may not get any flow of hot water. A TVR on its own doesn't cure this. Once the system is balanced you can use the TRVs to shut off the radiators once the TVR has detected the set temperature
An explanation.
I was planning to let the TRVs do that for me, what is the point of crawling round playing with the lockshields AND fitting TRVs?
If the system isn't balanced when you turn your heating on from cold one or more radiators may not get hot at all UNTIL maybe one or more of the TRV elsewhere in the system starts closing down. BUT, then your room stat may/will stop calling for heat and the boiler closes down resulting in zero heat to the room where the radiator stays cold because of incorrect balancing. You balance the system first and them use the TRVs to control the temperature in each room.
In that case I wonder whether to save the money on the TRV's and just balance it on the lockshields? I am not after precise temperatures, I just want the bedrooms lower than the lounge/study whereas at the moment I have the opposite.
The point is that they don't do the same job! I explained in an earlier post that fitting TRVs doesn't remove the need to balance.
Balancing by using the lockshields to throttle the flow through the hottest radiators ensures that all radiators heat up at the same time with more or less the same temperature drop across each of them.
TRVs then save energy by turning off each rad as its room reaches the required temperature. The room with the roomstat shouldn't have a TRV, and should be set to warm up slightly more slowly than the other rooms. The room stat will then turn off the whole system when *that* room is up to temperature.
Sorry but I don't see the difference. I want the rooms to reach a certain temperature so surely I can achieve relative temperatures by adjusting the lockshield between barely open and a quarter and then the whole system with the hall stat or water temperature?
I think you are confusing balancing a system with controlling the heat.
Balancing is done by adjusting the flow through a particualr radiator(s) to ensure that all in the system heat up at approximately the same rate. Once the system is balanced then you would use a TRV to control the temperature in a particular room.
You only balance the system once, or once per change of the system - a change of radiator size, adding radiator or perhaps changing the hot water tank). You do this by leaving one radiator valve on each radiator fully open and go around each radiator and check that they are all reaching temperature. You adjust the second (lock shield) valve on all the radiators to achieve this condition - this is balancing the system.
Remember you may have a large radiator rated at 3kW in your main living room but smaller radiators rated at 1kW for the bedrooms. The difference in physical sizes, or number of panels/fins, takes into account that the system may have been designed in the first place for lower bedroom temperatures.
The temperature of each room can be controlled by setting the TVRs. Not all days require the same radiator control settings
For instance, on a cold winters day the sun is shining through the bedroom window and solar heating brings the bedroom temperature up to
18C but your main living room is on the other side of the building and doesn't get the sun. Ideally when you have the heating on you want the bedroom radiator to be fully off and the living room radiator to be on.On another winters day the sun isn't shining and the bedroom gets no solar heating, now with the heating on you want both the radiator in the bedroom and the one in your living room to be on.
A TRV in the bedroom will detect on the sunny day that the room is already at 18C and turn the radiator off but on the day without sun the TVR will detect the bedroom is at a lower temperature and leave the radiator on until 18C is reached. If you didn't have a TVR you would have to manually adjust each day to achieve the same result.
A simplistic example because there are other factors resulting in high bedroom temperatures. If you leave all doors open hot air will rise from downstairs and heat the bedrooms.
Because one will result is a properly balanced system and the other will not.
Any "balancing" that relies on TRVs will result in rooms that heat unevenly, since you will get some rooms getting practically no heat at all until other rooms fully reach set temperature. So you get hot and cold areas around the place. You also run the heating on part load for longer as it tries to get the last few rooms up to temp. If this is below the minimum modulation output of the boiler, then it will have to cycle to control the heat input. Thus extra fuel use and expense.
When you balance the system manually you'll have it set up correctly for that particular day, with the sun, wind and temperature.
The TRVs will give you weather compensation on a per room basis.
You're describing the way a system was before TRVs were possible, and you had to fiddle with radiators at different times of year.
Andy
Adding TVRs don't balance the system and are not a substitute for not doing so. Once a system is properly balanced the TVRs automatically make the adjustments for rooms being heated by the sun shining through windows etc.
OK, many thanks to Roger and others for the explanation :-)
I will go the whole hog. Once the new radiator is in I will balance the system (sounds like a good excuse for buying an IR thermometer) and then use the TRVs to maintain room temperatures at a level I like, pretty low for the spared bedroom (used to store old computers), higher in the lounge where I sit and try to find something worth watching on TV to the bedroom
- somewhere in the middle!
Thank you all for your patience.
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