Please help. We just rented this house and now realize why the walk through was so quick. Most important concern is that the toilets are filling with hot water!! ( In addition matter bath runs constantly, I just bought a new stopper last night, which should fix running water) we have NO WATER PRESSURE. The owner told us as far as maintenance for us to take care of small things ourselves, but if something more serious his responsibility.
Plumbing issues are not small things and should be the responsibility of the landlord.
It sounds like there is a toilet mixing valve that has failed or was installed improperly. In places where the water supply is very cold a mixing valve is used to take the chill off of the water going to the tank to eliminate condensation on the size of the tank.
It is possible that the mixing valve was not set properly and that you could adjust the screw that regulates the amount of hot water mixing with the Cold water.
If you can locate the mixing valve that is a simple fix that you could take care of yourself anything else I would inform the landlord that it is their responsibility to remedy the situation. The valve is usually located in an accessible place such as the crawlspace under the house or in the mechanical room where the hot water heater is or it is possible but not probable that there is an access panel on the backside of the wall that the toilet sits against.
If your mixing valve is like the one that I linked to there is a screw adjustment on One side of the valve that can be adjusted with a slotted screwdriver, screwing it in reduces the amount of hot water aloud through the valves.
If it is a mixing valve issue I don’t think that would account for the lack of water pressure. That is something that is certainly going to have to be addressed by a professional plumber.
Is the water pressure issue a problem with all of your Faucets or just the toilet?